Mikel Arteta admitted Premier League leaders Arsenal lacked composure in their shock 1-0 defeat at struggling Everton on Saturday.
James Tarkowski's second half header condemned Arsenal to just their second league loss this term.
It was a frustrating blow for Gunners boss Arteta, who had hoped to open up an eight-point lead over second placed Manchester City.
For the first time since losing at Manchester United in September, Arsenal tasted defeat and Arteta claimed his players weren't composed enough to cope with Everton's aggressive game-plan under new boss Sean Dyche.
"We had loads of the ball but we lacked that purpose and quality in the final third, we generated many chances. But then we conceded and they slowed the game down and we struggled," Arteta said.
"Everton do this to every team that is their strength with the height, the physicality is their strength, if you want to control the game against them you have to control this. We did not do that today.
"We needed more composure and to control emotionally the game better. We gave away so many unnecessary free-kicks and that's what they want."
Manchester City could close the gap on Arsenal to two points if they win at Tottenham on Sunday.
But, despite his criticism of their tepid performance at Everton, Arteta backed his players to survive the tense title race.
"Today I love them much better than the week before or a month ago. It is easy to be next to someone when they are winning well. I am still so proud of all of these players, they deserve it," he said.
"This is not going to be a rose pathway. This is going to be tricky and we will have to dig in and play much better than we did today."
smg/nr
