Arsenal manager Arsene Wenger bemoaned the referee's decision to award the opposition a late corner as his side slumped to a 2-1 defeat at the hands of Everton on Tuesday night.
The Gunners claimed the lead through Alexis Sanchez's deflected free-kick, only for Seamus Coleman to level matters on the stroke of half-time.
And, with time running out in the second half, Everton would go on to claim the lead through Ashley Williams' headed goal.
Referee Mark Clattenburg's decision to award the corner that led to the match-winner irked Wenger, while the Frenchman also bemoaned his side's inability to put the game to bed when they were on top in the first half.
"It was not a corner," Wenger said. "You could see from our side it was no corner.
"But I think we have to live with a wrong decision and it does not explain why we did not head the ball after.
"I think I am really disappointed because Clattenburg was in a very good position to see they headed the ball out and it's not the first time we are unlucky with this decision this season.
"Overall, I do not want to speak about the referee too much. It is not my problem."
He added: "I think we have to look at ourselves. We lost the game, I felt we started well and after that maybe lost a bit of urgency because we were a bit too comfortable and Everton made it very physical.
"Overall, I believe that from then on it disturbed our game and we created less flow going forward.
"In the end we didn't take our chance or two, we didn't create many but we had clear-cut chances in the game that we didn't take, and after that, you can be caught on a corner away from home."