Pep Guardiola admitted that Manchester City’s fragility was exposed by Arsenal as they were blown away in the final half-hour to leave their Premier League title defence in tatters.

Erling Haaland equalised Martin Ødegaard’s opener after the break but Arsenal hit back with four unanswered goals as Mikel Arteta’s side recorded their biggest win against City since a 5-1 victory at Maine Road in February 2003. Arsenal now find themselves six points behind the leaders, Liverpool, who play their game in hand against Everton on 12 February, with City a further nine points behind in fourth spot.

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It was the first time Guardiola has lost by a four-goal margin since becoming a manager in 2007, with City now having conceded four goals on four occasions this season. The City manager acknowledged their standards had dropped after Thomas Partey restored Arsenal’s lead following a loose pass from Phil Foden.

“The feeling is why we have not done in the last 20, 25 minutes what we had done well for the first 60,” Guardiola said. “Now we have to reflect and talk with the players and hope that it doesn’t happen again.”

Asked whether their second‑half collapse was due to his squad’s fragile confidence after a season in which City have lost seven Premier League games, he said: “It can be fragile because it happens so many times. But we have a duty to learn and there are always margins to get better. It’s happened all season, we are giving away too many things, we are aware this cannot happen, it happened.”

John Stones was at fault for Arsenal’s first two goals and he apologised to the City fans for the team’s performance in the final half‑hour. “It is hard to put into words straight after a game like that. Pride hurts. Sorry to the fans that have travelled to come and watch that,” he said. “How we played in the last 30 minutes was not acceptable. Personally and collectively, it’s not us.

“It is not nice to be involved in that when you know it’s not your team in those situations. We were in the game and it was a swinging point. It swung the wrong way for us. I am angry, upset personally and collectively about how the game finished. There are a lot of different things that I still haven’t figured out as to why it hasn’t clicked. The heart’s there, the passion’s there; everyone’s got the right intention. We all need to stick together.”

Arteta was understandably delighted with the performance and result as Arsenal made it five matches without defeat against City. “It’s a great day for us – for the result and the manner that we did it,” he said. “We were very aggressive and we played with a lot of courage.”

The Arsenal manager also said that he had been surprised by Myles Lewis-Skelly’s first senior goal that the 18-year-old celebrated by performing the “Zen” celebration usually favoured by Haaland.

“I wasn’t expecting it,” he said. “He’s got it inside him, he feels it and he’s very good at expressing it as well, and some players struggle with that. He does it in every action, he does it with his body language, he does it with his facial expression, how he lives the game, and then with the ball, because he takes it and he wants to make things happen, he takes risks, he takes initiative, and at his age that’s not easy to see.”

Asked about Lewis-Skelly’s celebration, Declan Rice said: “It’s football antics. Things happen on the pitch. He celebrated. It’s obviously the Haaland celebration. I know he has respect for him, the whole team has big respect for him because of what he’s done, he’s a big player.”