There were 63 minutes on the Emirates Stadium clock and the Arsenal crowd were in a state of extreme agitation. William Saliba had the ball at the back and he was taking his time – largely because there was nothing on for him. The fans screamed at him to hurry up. To do something. Anything. It was all going wrong because Chelsea were not just level at 1-1, they had dominated the second half up to that point.

On the right flank, Jurriën Timber held out his arms and gestured for everybody to calm down. Arsenal would be fine if they could keep their focus and do their stuff. It took Timber precisely three minutes to practice what he preached. When Declan Rice arced over a corner, it was Timber who wriggled free to head home what would prove to be the winner.

It was another fraught occasion for Arsenal and it remained that way until the very end. Moisés Caicedo banged just wide of the top corner for Chelsea on 87 minutes and there was the moment when Alejandro Garnacho, on as a substitute for the visitors, crossed for João Pedro and watched the ball go all the way through for the far corner. David Raya flung himself across to make a stunning stop. It was not the only time that the goalkeeper saved his team.

There was still time in the six additional minutes for another Chelsea substitute, Liam Delap, to put the ball in the net only for João Pedro to be flagged offside in the build-up and Arsenal’s relief when the final whistle went was palpable.

It was some distance from being a freewheeling performance from Mikel Arteta’s team. They laboured for long spells in open play, struggling for cohesion, their opening goal also coming from a corner, Saliba heading in. Quite simply, they found a way, Arteta getting the better of Chelsea – as he always seems to do. The lead over Manchester City at the top of the table is back up to five points, albeit Arsenal have played an extra game.

For Chelsea, there was only frustration, the sense of them being their own worst enemies, self-inflicted wounds to the fore, as they tasted defeat in the Premier League for the first time under Liam Rosenior. Their first-half equaliser came from a corner, the ball going in off the unfortunate Arsenal left-back, Piero Hincapié, but Chelsea were undermined by further sloppiness on defensive set pieces – they have now conceded seven goals from them in 13 matches under Rosenior. Then there was the red card, another red card, the ninth for their players in all competitions this season.

It was Pedro Neto who collected it for a swipe at the Arsenal substitute Gabriel Martinelli shortly after Timber’s goal. The winger was on a booking – for dissent – so he knew what was coming when he went in high on Martinelli in a desperate attempt to stop him on a counter up the left. He did not need to make the challenge because he had cover and Martinelli was a long way from goal. Nobody knows how Chelsea would have fared with 11 men. They did pretty well with 10. Arsenal held them off – just about.

It was physical. It was tight. Arsenal panicked the Chelsea goalkeeper, Robert Sánchez, with their high press in the early going and they took a familiar route to the breakthrough – an inswinging corner, big men loaded into the penalty area. The delivery came from Bukayo Saka and it was a prodigious leap from Gabriel Magalhães beyond the far post, defined by the hang time. When he nodded back and inside, Saliba was there to flick home, the ball going in off Mamadou Sarr, to whom Rosenior had given a full Premier League debut.

The story of the first half was set pieces – partly because there was precious little creativity in open play. Sarr fluffed a big chance on the volley in the 11th minute after a free-kick was dropped into the area for him; he was unmarked and the Chelsea equaliser came from an inswinging corner, sent over by Reece James.

The visitors appeared to have got the move to work moments earlier only for Raya to reach back and produce an excellent save when James’s corner came off Declan Rice’s elbow. One question: how was it not a penalty? Rice had wrestled with Jorrel Hato and seemed to make an unnatural movement with his arm towards the ball. He was also all over Hato.

Chelsea’s grievance floated away when Hincapié suffered his aberration. He wanted to get distance on his clearing header when he rose at the near post only to misjudge it, the ball flicking off the top of his head and flying into the far corner.

Chelsea called the tune after restart. Enzo Fernández extended Raya with a low shot from distance and the goalkeeper would keep out a João Pedro header following a corner. When James crossed just before the hour, João Pedro flashed another header wide.

What did Arsenal have by way of response? Another set piece, of course, Timber outmuscling Sarr to score. Chelsea raged about a push somewhere in the crowded area and Neto was booked for taking the protest too far. Which only made what he did next feel so crazy. Eberechi Eze worked Sánchez in the 80th minute but Arsenal could not see out the win with any comfort. At least they saw it out.