Arsene Wenger has criticised referee Mark Clattenburg's decision to award Everton the late corner that led to Ashley Williams' winner in Arsenal's 2-1 defeat at Goodison Park on Tuesday.
The Gunners conceded from a corner for the first time in the league this season after Clattenburg decided Laurent Koscielny, not Everton substitute Dominic Calvert-Lewin, got the final touch in the Arsenal box.
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Williams headed home the resulting set-piece in the 86th minute, completing the hosts' comeback after Seamus Coleman had cancelled out Alexis Sanchez's deflected free-kick.
The defeat saw Arsenal miss the chance to go top of the Premier League table, __with league leaders Chelsea to play Sunderland on Wednesday, and Wenger admitted he was left "really disappointed" by the decision.
"It was not a corner," he 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."
Arsenal had looked in control when Williams turned Sanchez's free-kick past Maarten Stekelenburg after 20 minutes, but poor marking allowed Coleman to equalise on the stroke of half-time.
And after Williams took advantage of more slack defending to score the winner, Wenger conceded his side lost urgency in the second half.
"I think we have to look at ourselves," Wenger added. "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."
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