Arsenal gave away a cheap goal in the first half when Shkodran Mustafi completely misplayed an aerial duel with Sergio Aguero and allowed the striker to run clear through on goal, then collapsed in the second half after Vincent Kompany doubled the lead in the 58th minute.

Kompany steered in a shot from Ilkay Gundogan after a corner -- with Leroy Sane standing in an offside position but not affecting play -- while David Silva netted the third seven minutes later to end all resistance.

"I feel that a little bit everything went against us today and we self-inflicted our punishment," Wenger told a news conference. "Because we had an unbelievable chance at 0-0, we gave them a goal that was the 1-0.

"We were a bit unlucky in the second half, even if I think we didn't start well at all in the second half and got punished. But the second goal is offside. I don't know who sat in the VAR, I just watched it again, it's a mystery for me how you can watch that on replay and not give offside.

"After that it was game over and City controlled the game and was better than us from then on. So well done to them."

Video-assisted replays were in use for the game but there was never an indication that referee Craig Pawson consulted it on either of City's goals. Wenger said Mustafi thought he had had been fouled by Aguero on the first goal but admitted that there was no "obvious" push.

Arsenal's players looked deflated after that second goal and were harshly criticised on TV by pundits, including Sky Sports' Gary Neville, for a perceived lack of effort in the second half.

Wenger, though, didn't want to comment on the criticism -- instead questioning why there wasn't more added time at the end despite a couple of extended injury breaks.

"When you lose a game like that everything is questioned, the players," Wenger said. "We played against a good side, you cannot say we played against an average side, they dominate the Premier League. At 3-0 it's difficult. It's difficult to come back.

"And the referee doesn't give the injury time, the added time, regularly. When I said why don't you give more time, he told me, 'why do you want more time?' I told him it's not down to you to judge how long is the time, if we want it or not, give the normal added time."

Wenger reverted to a back-three for this game after largely ditching that system in recent months. It worked well until Mustafi's howler, and Wenger said the tactics weren't to blame for the loss.

"[I used a back-three] because we conceded goals in big games and at Wembley we did well with three centre-backs last year against them as well," Wenger said. "And I think we controlled them well in the first half. Defensively they were quite nervous. And overall I believe the goals we conceded could not be explained by the fact that we played with three at the back. I don't think the system was especially questioned by that."

Arsenal will face Man City again on Thursday in the Premier League -- a match that was originally scheduled for Sunday -- with the Gunners badly needing a win to keep alive their hopes of climbing back into the top four. But Wenger admitted this result will give City a mental edge going into that match.

"It doesn't help because they will be on a high and we will have to recover from the disappointment. On that front, they will have the advantage," he said.