And that’s us done for this session. Stay tuned for Tumaini Carayol’s report from today’s action.

Tiafoe has been superb recently, he’s asked why. “I don’t want to put any secrets out,” he says with a laugh. “I’m coming forward and I’m having fun. Put that altogether and you’re in the quarter-finals of the US Open.”

Tiafoe is 10-0 on Louis Armstrong. He’s asked about why he loves the venue. “It’s been amazing playing in this court, the energy is amazing. It’s the people’s court,” he says.

A brilliant performance from Frances Tiafoe, who looked sound in every aspect of his game today. He will face compatriot Alex Michelsen in the quarters.

A superb backhand from Tiafoe leaves Medvedev sprawling and it’s match point for the American …

Tiafoe to serve 4-5 down. Medvedev can only return the first serve into the net and we’re level at 5-5. After a long rally, Tiafoe hits long and Medvedev has set point on his own serve at 6-5. But some superb work at the net, from Tiafoe this time, level the score at 6-6. The New York crowd roar in appreciation.

Tiafoe looks to have held serve with a drop shot but some lovely play at the net from Medvedev gives him the mini-break at 4-3. But he can’t consolidate and we’re back on serve again at 4-4.

And a double fault from Medvedev kills his momentum and we’re at 2-2 on serve in the tiebreak. He makes it 3-2 before we head to Tiafoe’s serve and a strong serve helps him to 3-3 as we change ends.

Medvedev gets the first break of the tiebreak to lead 2-1 and gain a crucial advantage as he attempts to stay in the match.

Big Foe has volleyed superbly today, taking advantage of Medvedev’s position behind the baseline – he’s pretty far back now, having spent some time on the paint – to sneak in. He holds to 15, so here comes a potentially decisive breaker … which Tom Lutz will bring you. So it’s goodnight from me, and good evening from him.

Tiafoe has handled pressure really well today, holding to 15 to stay in the set at 5-5. And as if to prove how comfy he is out there, a forehand on the run changes the complexion of the rally, then a perfect drop takes him to 15-all. But from there, Medvedev quickly secures his hold; can Tiafoe do likewise and force a breaker?

…but Medvedev isn’t having it, serving his way out of immediate danger to lead 5-4 in the third.

And then there was one;,Tiafoe leading Medvedev 2-0 4-4, and at 15-30, he has a chance to try and get the match finished…

Michelsen is every bit as happy as you’d expect. He’s not dropped a set in the tournament and isn’t “super-surprised” with his progress as he’s been working hard for years. He’s 0-4 against Tiafoe and 0-2 against Medvedev, but if he plays the former it’d probably be on Ashe, a once-in-a-lifetime occasion.

Michelsen though, plays a really good point, a second serve catching the edge of the service box and a backhand volley bringing us to deuce; a big serve saves him when he’s down advantage. Meantime, Tiafoe hods to love, a pirouette at net helping him find a volley for a ball that’s behind him, obscene behaviour, and he leads 2-0 3-3.

A 57-second hold for Medvedev, who trails 0-2 3-2; Michelsen is under pressure serving for the match at 30-40.

This is a really excellent performance from Tiafoe – though there were breaks in set one, he’s looked dialled-in throughout and his shot-selection has been very good. But he nets for deuce serving at 2-1, while on Grandstand, Etcheverry holds, meaning Michelsen must serve for the match at 7-6 6-5 5-4.

As they are now, Tiafoe making 15-40 then collaring a return lashed down the line; we’re back oin serve in third, the American by two sets to love.

Indeed he can. Annoyingly, my coverage drops out, returning in time for me to see that he’s broken for 0-2 2-0, still in this thing and fighting, The problem he has is not really having the weapons to blow opponents away, which means in big matches, things are necessarily difficult for him.

I’m really enjoying Tiafoe’s performance today – I like the way he’s mixing it up and taking it to Medvedev, expecting to win. Medvedev, though, holds for 0-2 1-0, then ushers a backhand down the line for a winer and 0-15. Can he parlay the start into something more significant?

It looks like we’re getting all-American quarter, Michelsen finding a winner for 30-40, then unleashing a forehand before sealing the break with an overhead. He leads 2-0 3-2, and is three holds away.

Both players leave court; on Grandstand, Michelsen leads Etcheberry 2-0 2-2.

Brilliant from Tiafoe, making advantage then changing the flow of the next point with a forehand coming in. But there’s work yet to do, an over-the-shoulder backhand volley followed by another, and Armstrong explodes, Big Foe beating his big chest. He leads 7-6 6-4, and Medvedev is in deep trouble.

Medvedev holds, forcing Tiafoe to serve for the set, and he controls his emotions well, skipping in to guide a backhand winner down the line for 15-all; a service winner follows. So when a return is netted, he holds two set points, missing the first … and the second, losing patience in a long rally and hitting long. To deuce we go, tension ratcheting up.

Lovely from Medvedev who, at 30-all, clobbers a backhand to the corner, then makes space at net to raise break point with a tricky putaway. Tiafoe, though, eager to hang on to his break, finds a service winner followed by an outstanding stooping volley almost from behind him – the return was goodun too – then secures a crucial hold with another gigantic delivery. BF leads 7-6 5-3, a game away from the second set.

Tiafoe holds for 7-6 4-2 and this set is progressing much more swiftly that it’s forebear; Medvedev quickly arranges a hold of his own to keep his opponent honest, but he’s running out of road in this set.

Michelsea makes 40-15, wallops down an ace, and leads Etcheverry 7-6 6-4. It’ll take something monumental for the clay-court specialist to come back from here.

At 2-2, a Tiafoe drop and overhead earns him 15-40, and he then finds a terrific angle on the forehand when going cross, cutting the court in half and opening the space for a flat one down the line of frankly terrifying power. It feels like a big moment in the match and, at 7-6 3-2, he leads by a set and a break.

Michelsen holds for 7-6 5-3, and he’s a game away from taking a 2-0 lead. The winners of the two matches currently on court meet in the last eight.

“Thank you for sharing this tremendous interview,” emails Martin Davies. “Number five was a genuine WTF moment for those of us who remember Alan McGee signing him to Creation in 1997. Also, McConaughey has a very silly high laugh completely at odds with his regular voice.”

It’s great, isn’t it? And what a boss his older brother sounds.

Tiafoe holds, then from 40-0, fights back to deuce; trouble for Medvedev, who serves a double when up advantage. But from there, he secures his hold and a 2-1 lead in the second.

Gah, only berry ones left. Why do bad things happen to good people? Medvedev holds easily at the start of set two, while Michelsen leads Etcheverry 7-6 4-2.

And Tiafoe is soon bouncing, taking the breaker 7-1 after a 74-minute set. Medvedev will be feeling very, very poorly after putting so much into that; by way of empathy, I’m off downstairs to grab a Fruit-Pastille lolly.

Tiafoe snatches an early mini-break, consolidating it with an inside-out forehand that’s almost a table-tennis shot, cranking up serious power. And another break, then another, take him to 6-1, a tight set suddenly accelerating, Medvedev perhaps still smarting after making a mess of serving it out.

At 30-15, a double gives Tiafoe a sniff, then a forehand winner earns break-back point and a netted backhand means that, after 68 minutes, it’s 6-6. These two are really well-matched.

That’s in on Ashe for the day sesh, but on Armstrong, there’s Pegula v Cirstea to come – though I think we’ll be finished before that starts. For now, Medvedev and Tiafoe are locked at 5-5, but the former has two break points, the latter misses a forehand, and at 6-5, the 2021 champ will shortly serve for a fluctuating and punishing first set. On Grandstand, Michelsen has broken in set two to lead Etcheverry 7-6 2-0.

We’re on serve on Armstrong, Tiafoe up 5-4 on Medvedev. Meantime, Alcaraz is happy with his performance, saying he tried to put pressure on the return game. Is he back to his best? “I think so, ahahahaha!”

It really is absurd how good he is so young, and how honest he is about it in a way that’s not remotely arrogant or overbearing. He already has seven majors, and if he can stay fit, he’s going to end up with more than Djokovic.

Having held for 4-4, Medevev races in to flick a winner that makes 15-0, but let’s move to Ashe, where Paul is fighting with all he’s got, earning two break points only to ruin the first with a tame slice into the net and only for Alcaraz to seize the second with a swing-volley from well back. His forehand is so good it feels like cheating and, as I type, he unleashes a flat one cross-court with such power and whip it’d be illegal in some countries. Er, his wrist seems in OK nick on balance, and he’s got match point, ridiculous genius that he is.

Good work from Michelsen, taking back the mini-break when set-point down before earning one of his own. And, in a bruising rally, he finally ends it with an overhead at net to lead Etcheverry 7-6( 6).

But before he can, Medvedev, perhaps a little further back behind the baseline now, retrieves Tiafoe’s break and trails 3-4, Those seven games have taken 45 minutes. On the other hand, Alcaraz is breezing by Paul, who’s just held, forcing him to serve for the match at 6-4 6-3 5-3.

I nip for a … comfort break, so of course Tiafoe takes the opportunity to break and leads 4-2 in the first; on Grandstand, Ethcheverry leads Michelsen 5-4 with a break in the breaker and as I type, earns set point.

A straightforward hold for Tiafoe, who leads Medvedev 3-2, and the same for Alcaraz, who’s up 2-0 4-2 on Paul. His defensive work today has been especially incredible, but his next match, against Shelton or Tsitsipas, should be much more of a test – especially if they can take him deep, into rallies and sets. Is he ready for a long, physical match? I mean, almost definitely yes, but that feels the field’s best hope.

Matthew McConnaughey is in the crowd, excuse enough to post this interview I really enjoyed.

Tiafoe holds, then takes Medvedev to deuce on serve, prior to burning a break point. An ace follows, then a Big Foe forehand down the line drops long, taking us to 2-2. This contest is going to age these two several years

Alcaraz holds then makes 0-40, but Paul saves three more break points. He’ll not be chuffed he’s having to face them but he’s showing proper fortitude in trying to deal; problem is, the pressure tells, Alcaraz stopping in the next rally with ludicrous athleticism, eventually eliciting the error. Then, at the net, he somehow reacts to volley when a ball is hit at him – that’s a mostake from Paul, who loads at which to aim, one he compounds but hitting wide, again with options. The champ leads 2-0 2-1, and this display is ominous for the rest of the field.

A big hold for Paul to open set three, who has a proper job on trying to convince himself he’s not already done for. On Armstrong, meanwhile, Medvedev is standing closer to the line than usual, while Tiafoe is looking to come in where possible, and he breaks back through deuce. Already, this has the feel of an epic.

A long game to open up, Medvedev showing he’s ready to suffer and asking Tiafoe if he wants to come with, breaking for 1-0. Back on Grandstand, Etcheverry has broken Michelsen back and those two are now level at 3-3 in the first.

A delicious drop from Alcaraz earns him set point, he drives it home with a nails serve, and this is some very serious tennising. Paul is playing pretty well and can’t even get close to close. The champ leads 6-4 6-3 and looks to be nicely recovered; it’ll take something to beat him here.

Alcaraz is just way too good for Paul, making 0-15 for the sixth return-game on the spin. Paul, though, serves his way out of trouble, securing the hold, but must now break to stay in the set. Meantime, Medvedev and Tiafoe have just got going while, on Grandstand, Michelsen leads Etcheverry 3-1.

Alcaraz looks he’s playing in pair of policeman’s shoes. It’s very strange indeed, of Nike for giving him such footwear and of him not to tell them to go again. He holds to 15 for 6-4 5-2, playing beautifully, and is within a game of the second set.

Paul does really well to save all three, then another on advantage, then another with a service winner, then another. And when he makes game-point of his own, Alcaraz nets a backhand, the crowd are extremely chuffed for him, and he’s still in this set, just about, at 4-6 2-4. Meantime, on Armstrong, Tiafoe and Medvedev are out.

Back with our men’s champ, Alcaraz has broken Paul in set two to lead 6-4 4-1, and he has three points for the double break.

Next on Armstrong; Daniil Medvedev (7) v Francis Tiafoe (11).

Noskova is a helluva player, and at just 21, we’re going to see helluva lot of her over the next decade. And the same is so of Kostyuk, who I think has a more varied game, but for now, Noskova’s power is giving her the edge.

Oh, and hi again all.

Noskova is relieved to have won a match tougher emotionally than physically – and it was taxing in that aspect too. She’s won 11 grand slam matches in a row but doesn’t feel like she can win every match. Marta is a huge competitor and she knew it’d be a tough match; it was especially hard to get going again in the third set.

She’s a wrestling fan and had Charlotte Flair in her box the other day, which she enjoyed a lot. And that’s our lot; what a match.

A ferocious crosscourt forehand from Alcaraz brings three break points … and he only needs one to lead Paul 6-4 2-0. ‘Alcaraz has this match by the scruff of the neck,’ says Tim Henman on Sky. Kostyuk holds to 30 on Armstrong but Noskova will be serving for the match.

Noskova’s booming backhand on the line at 30-30 sets up game point – and the Wimbledon champion moves to one game from victory. She leads Kostyuk 5-3 in the deciding set.

We have the third straight break of serve on Armstrong. Noskova seals a 4-3 lead, on her third break point, with a powerful and precise backhand.

Alcaraz wins the first set 6-4. He raced to love-40, despite Paul getting in three first serves. Paul saved the first break point of the set with an ace but is unable to save the second.

Kostyuk breaks. A long forehand from Noskova on 30-40 bring us level in the decider. On Ashe, Paul is serving to stay in the first set at 4-5.

Noskova breaks. After a brilliant Noskova forehand brings up deuce, Kostyuk’s level drops on the next two points and the Wimbledon champion now leads 3-2 with the first break in the decider. We’re still on serve on Ashe (4-4).

Noskova is in control of her service game at 40-15 but a couple of loose points allows Kostyuk back in. Unlike the end of the second set, Noskova responds and we continue with serve in the third (2-2).

The beginning of the third set on Armstrong is providing little drama as Kostyuk holds. On Ashe, Paul is taken to deuce but two powerful serves help him get over the line and it’s 3-3.

Noskova responds by winning her first service game of the third set to love.

Kostyuk has the serve to open the third set and she makes it five games in a row with a comfortable hold. How will Noskova respond?

‘The crowd around me are just gasping,’ says Laura Robson, who is courtside for Alcaraz v Paul for Sky, after four high-quality games. We’re still with serve on Ashe.

Kostyuk wins the second set 7-5. Noskova, who had two match points in her previous service games, is out of sorts and is broken to love. Who saw this coming 15 minutes ago? We’re going to a decider.

Kostyuk, a wild backhand aside, comfortably holds to make it 6-5. Alcaraz is taken to deuce but holds and we’re going with serve on Ashe after three games.

Kostyuk saves two match points and the crowd in Armstrong show their appreciation. They do again when she wins in a third point in a row and, would you believe it, Kostyuk only goes and wins a fourth in a row to make it 5-5 in the second set. On Ashe, Alcaraz and Paul have shared the first two games.

Kostyuk easily holds but she now needs to win the next game on Noskova’s serve to stay in the US Open.

Back on Armstrong and Noskova is now one game away from the quarter-finals.

The defending men’s champion, Carlos Alcaraz, is about to start his fourth-round match against the American 20th seed Tommy Paul. Alcaraz has won six of their previous eight meetings.

Kostyuk is in trouble. At 15-15 she finds the net with a poor backhand then follows that with a double fault. She finds the net again and Noskova takes charge with the first break in the second set. Noskova leads 7-5 4-3. She is two games away from the quarter-finals.

Alcaraz and Paul are now warming up on Ashe while Noskova makes it 3-3 in the second set on Armstrong.

Carlos Alcaraz is juggling some tennis balls as he prepares for his upcoming match against Tommy Paul on Arthur Ashe court. Back on Armstrong, it is Kostyuk’s turn to race through a service game and the second set continues on serve.

Noskova wins the first point of the third game in the second set but then it is all Kostyuk, who throws in an ace and lovely volley to lead 2-1. The shadow is now almost covering half of the court in Louis Armstrong Stadium. Noskova then races through her service game. Noskova leads 7-5 2-2

Another mistimed forehand from Kostyuk, on break point, allows Noskova to escape to deuce. One long return and one long forehand later and Noskova has levelled at 1-1.

Kostyuk wins the first game of the second set by holding to 15. A much-needed game for the 11th seed. She even served her first ace of the match.

Noskova wins the first set 7-5. There’s not been much in it but the sixth seed has won the key moments, breaking Kostyuk’s serve three times.

Noskova breaks. A sweet forehand into the corner from Noskova gives her break point, which is then won when Kostyuk mistimes a forehand from the near the centre of the baseline. The Wimbledon champion will be serving for the first set.

After the mistake in her previous service game, Noskova does not miss an overhead at 30-30 this time and a delicate volley in the following pointsecures the game. 5-5

The only problem Kostyuk has on her serve is a double-fault at 40-love, which is surely the ideal time to have one. Noskova now has to serve at 4-5 to stay in the first set.

4-4 Kostyuk ups the tempo to break straight back. She shrugs off a wild forehand at 15-all and at 30-all Noskova has an easy-looking overhead but finds the net to give the Ukrainian break point – which she takes. The commentators on Sky are suggesting the sun may have affected Noskova’s sight for the poor overhead.

Noskova 4-3 Kostyuk A double-fault at 30-all gives Noskova break point. Kostyuk’s first serve hits the net and the second is perhaps too short which allows Noskova to take control of the point and break for the second time.

Noskova 3-3 Kostyuk Hello all. A comfortable service game, held to 15, from Noskova.

Aaarrgghh my temperamental computer forsook me, but it’s back now, so I can a) let you know it’s tight on Armstrong, Kostyuk and Noskova level at 2-2, and b) Stephen Flynn is here to chill with you for the next bit.

Next on Ashe (but not for 56 minutes): Tommy Paul (20) v Carlos Alcaraz (2).

Sabalenka praises Townsend as a really good player and focused, saying she’s hard to play, especially in New York, and thanking the crowd for respecting her. She wanted to play not just point by point but ball by ball, but allow me to interrupt her because Kostyuk has just flowed a gorgeous backhand cross-court to break Noskova back after a protracted game. She’s into the match, and it might just turn out to be as good as we’re hoping.

Sabalenka consolidates for a 6-4 5-3 lead. She’s not made this easy for herself, and will have to play better whoever she meets next, assuming she progresses, but we can be pretty sure she will.

Sure enough, she races to 0-40, and inside-out return lands close to the baseline, and she can’t adjust fast enough to do anything other than net. Sabalenka leads 6-4 4-3 and is close to the quarters – where she’ll meet Noskova or Kostyuk, their match just under way. And no one will be surprised to learn the former has started slowly, broken to 15; at some point, she’ll find a way of managing her nerves, but she’s not there yet.

Sabalenka now leads Townsend 6-4 3-3 and I’d not be surprised to see her break next game, taking the chance to break the back of the match.

Noskova and Kostyuk are out on to Armstrong and, thinking about it, they’re actually quite similar as players, excellent athletes who are strong from the back but don’t love pressure, especially when serving. Meantime, Sabalenka breaks back, Townsend just not able to sustain a level that gives her a chance to win.

Serving at 6-4 1-2, Sabalenka again finds herself trailing at 15-30, then a forehand error means 30-40 … and then Townsend does something, but my screen freezes so I don’t see what. Nevertheless, it’s enough for the eighth break of the match, and she trails 4-6 but leads 3-1; can she consolidate?

Next on Armstrong: Marta Kostyuk (11) v Linda Noskova (6). I can’t wait for this one.

By the way, it can’t be only me singing this every time anyone mentions Alexandras Eala.

Townsend’s charging the net whenever possible, daring Sabalenka to pass her, which makes a lot of sense – the champ isn’t at her best, so pretty much has to go for the shots, because she knows the doubles volleying isn’t to be messed with. She holds – I know! – for 1-0 in set two having lost the first.

Townsend makes 15-30; pressure for Sabalenka, who responds well, with a service winner, then makes 40-30. Oh, but have a look, the American taking a return early and hooking it line into the corner for deuce … only for the champ to power through it, a thumping forehand securing a 6-4 opening set.

I was sad to hear what Oor Maddy had to say about her struggles following her defeat to Qinwen Zheng having burned a 5-0 final-set lead.

“I feel like I got off to a really good lead and then I just got really scared. I felt like I couldn’t swing. Tennis just feels really hard right now. I feel like that kind of took over.

“I think my level dropped and she started to play better. I just feel like I’ve kind of been struggling for a while now and I feel like I was able to play through it for a bit. I’m sure everyone could kind of see that I was struggling a bit. Inside it’s felt probably even bigger than that. Some weeks are easier than others. This week is obviously one of the harder ones just because you care so much. I’m gonna have to make some sort of changes.”

“I think it’s been something that’s been building for a while. I just kind of keep pushing it off and pushing it off because that’s how the tennis world works. It’s just to the point where I actually need to do something about it.”

Elite sport is hard.

Townsend holds for the first time – Sablenka has only done so once too – forcing the champ to serve for the set at 5-4. Meantime, on Armstrong, Patten/Heliovaara are a game away at 7-5 5-2.

Townsend does, though, make 0-30 … then 0-40, and when Sabalenka nets a forehand, she has one break back. That really was a nonsense game from the champ, who can play so much better than she has this year.

Yeah, I’m afraid this is going as predicted now, Sabalenka just too good. She breaks again for 5-2 – Townsend has yet to hold – and is now serving for the first set at 5-2.

Sabalenka breaks again and this time looks determined to consolidate; she does, as Heliovaara/Patten break Arnaldi/Struff for 7-5 3-1. The no 1 seeds are desperate to win this event, and it won’t be easy to stop them.

Townsend is going for it on return, hitting hard and looking to come in to use the volleying she’s honed playing doubles. She breaks back for a second time and looks to be enjoying the occasion.

Again, though, Sabalenka breaks the Townsend serve. She leads 2-1 and, though I’m going against the experts who expected a tight match, I don’t really see how she can win this. Sabalenka’s bottom level is just too high for her.

Two banging winners take Townsend to 0-30, as Heliovaara/Patten make 0-40 and three set points thanks to some sloppy stuff from Arnaldo/Struff … and take the second to secure a 7-5 lead. Meantime, Sabalenka is now down 15-40, sends down a double, and we’re back level at 1-1.

Heliovaara/Patten hold for 6-5 in the first, forcing Arnaldi/Struff to serve for a breaker, while Sabalenka burns various break points in game one before Townsend goes long hitting down the line on forehand. A statement start from the champ.

Taylor the Crow.

Townsend, by the way, has her own pop-up shop.

We’re 4-4 in the doubles and knocking up on Ashe. Thinking more about the match, I’d expect Townsend to use top spin to hit cross at Sabalenka’s backhand, taking her outside the lines if possible. She’ll also try and slow the game down, I think, and frustrate the champ, who doesn’t enjoy the wind-ups.

Townsend comes out wearing a coat that wouldn’t be out of place in the Night’s Watch, photo to follow but, in the meantime:

It’s worth remembering what Patten said after winning Wimbledon, given the attempts to take doubles prize money away from players who need it, in order to pay already well remunerated singles players just a bit more. Frankly, it stinks.

This is a fantastic example of the joy that doubles can bring. The crowd - I hope you enjoyed it. I believe we should be growing opportunities in tennis for kids, whether they are doubles players, singles players, British, Finnish, from El Salvador or Croatia, wherever they are from, we should be growing the support instead of taking opportunities away.

Arnaldi/Struff recover from 0-30 down to hold for 2-2, but it does feel like a break is in the post.

In roughly nine minutes’ time, Sabalenka and Townsend will step out on to Ashe. I imagine the American will use plenty of slice to take pace off the ball, forcing the champ to generate it all herself, while also seeking to haul her to net. I don’t really think she’s got a path to victory, but if there is one, this is probably it.

We’re away in our dubs, Heliovaara/Patten up 1-0 on Arnaldi/Struff and with a break point … saved when Heliovaara returns into the net.

Mark Kovacs adds that the idea against Medvedev is to take time away from an opponent who’s really good when he has it. I guess that’ll mean powerful, flat shots, and perhaps some crowding of him at net, especially if he stands as far back as he usually does.

On sky, we’re watching Tiafoe’s coach with Christian Harrison, who’s been a great addition to Sky’s commentary team over the last year or so. He’s really good at noticing stuff with a pro’s eye, and also at explaining it; we’re being told that Tiafoe has always had a great backhand cross, but he’s now much better at going line. I remember years ago, Calvin Betton, Henry Patten’s coach and our resident expert, told me he’d seen a brilliant kid – our man here – but until now, he’s not hit the level he suggested he might reach. He is, though, hinting that he might get there, at 28 older than is usually the case, but progress isn’t always linear.

Also going on: