No easy games? Surely this one would be for Arsenal. Never before in English football history had a team endured a worse league record after 15 matches than Wolves. In any of the professional divisions. Their haul of two points gave an outline of the grimness, although by no means all of the detail.

Before kick-off, the bookmakers had Wolves at 28-1 to win; it was 8-1 for the draw. You just had to hand it to the club’s 3,000 travelling fans who took up their full ticket allocation. There were no trains back to Wolverhampton after the game, obviously. It was a weekend. Mission impossible? This felt like the definition of it.

Yet Wolves would scrap and they would confound. For most of the occasion, it felt as if we were watching the shock result of the season play out. Arsenal were horribly off their game. The Premier League leaders might have cited fatigue as an excuse. It was also possible to wonder whether complacency was at work – in the Emirates Stadium stands, as well, where it was strangely flat and subdued, particularly in the first half.

Mikel Arteta’s team played their trump card on 70 minutes; from a corner, naturally. Little had gone for them in open play. It was Bukayo Saka who sent over the inswinger from the right and it was when Sam Johnstone’s world fell in. The Wolves goalkeeper misread the flight and, scrambling back, he seemed to brush the ball against the far post. Whereupon it bounced back, hit him and went in.

The crazy thing was that Rob Edwards’ visitors rebelled. Arsenal tried to protect what they had towards the end and they dropped deep, almost inviting their opponents on. Arteta would be furious about this afterwards.

Wolves pushed in the 89th minute, the Arsenal substitute Myles Lewis-Skelly needing to make an important tackle on Tolu Arokodare, who had also come off the bench. Then it happened. When another substitute, Mateus Mané, crossed from the left, Arokodare got in front of Piero Hincapié to flash a header past David Raya. The Emirates announcer gave the goal to Mané. But if he was scrambled, so was everybody.

Arsenal found the answer deep into stoppage time; a goal to avert disaster, to paper over the cracks. Just about. Arteta had sent on Gabriel Jesus and he challenged in front of goal when Saka crossed from the right. The ball, though, flew in off the head of Yerson Mosquera. Another own goal; devastation for him and Wolves. The defender lay supine for what felt like an age.

The relief for Arsenal was palpable. Arteta had seen his team’s lead at the top cut to two points after the 2-1 loss at Aston Villa the previous Saturday. He could not countenance another slip. He needed to apply the pressure on Manchester City before their visit to Crystal Palace on Sunday. The positive reading was that winning ugly is the hallmark of champions. It was certainly ugly.

“We had a period of two or three minutes [being] deep, totally passive, with horrible defensive habits,” Arteta said of that spell near the end. “That is nowhere near the level that is required. We are relieved because we managed to score a goal at the end and go on winning but we need to improve in that sense, for sure. We made it even harder with what we did in the manner that we conceded the goal. That’s unacceptable.”

Wolves had set an extraordinarily low bar with their performance in the 4-1 home defeat against Manchester United last Monday but even so, this was much better from them from the first whistle. The commitment was there, especially in the duels. Emmanuel Agbadou was a symbol of it at the back, slamming the door on Viktor Gyökeres. Toti was good alongside him and so was João Gomes in midfield.

Arsenal were terrible in the first half. So slow, so predictable. Pretty much everything in open play went through Saka on the right but try as he did and slippery as he was, he could not make it happen. Arteta’s team had only one big chance before the interval which, inevitably, came from an inswinging Declan Rice corner. Gabriel Martinelli was unmarked beyond the far post but he directed his header across goal and wide. Martinelli had two other flickers only to lack conviction.

The moment to quicken the pulses in the first half came at the other end, when Wolves broke after repelling a 27th minute corner. Hwang Hee-chan ran from his own half with nobody bar Raya in front of him and a posse of chasing red behind him; a cat among the pigeons. He kept running and unloaded the shot, Raya getting down to save. Hincapié did well to block from Jørgen Strand Larsen on 45 minutes after initially slipping over.

Arteta had gone as strong as possible with his lineup – no rest for many of his overexerted players – and the task was to plot a route through Edwards’s 5-3-2 system. William Saliba and Rice were back after absences and Arteta was forced into a reshuffle when Ben White, on a rare start at right-back, was forced off on the half-hour with a hamstring problem.

With almost an hour on the clock, it was impossible to ignore the anxiety in the home seats. Was it going to be one of those nights? The sluggishness of their team was hard to explain. Arteta made a triple change, introducing Mikel Merino, Martin Ødegaard and Leandro Trossard. Off went the ineffective Martín Zubimendi, Eberechi Eze and Martinelli, the last of whom had just curled a shot past the far post.

Arteta raged when Hwang slid into Lewis-Skelly and was booked – the manager wanted a red card, although there was not enough in it for that. Arteta watched Rice go close with a free-kick and then force a fine low save out of Johnstone. The goalkeeper’s descent from potential hero to villain was stunning, the first own goal of the night a real howler. The second brought Wolves to their knees.