Arsenal manager Arsene Wenger says Everton's physical approach managed to disturb the Gunners as they fell to their first away loss of the season at Goodison Park on Tuesday.
Ashley Williams headed in a later winner as Everton's 2-1 victory ended a 14-game unbeaten run for Arsenal in the Premier League, even though they had gone ahead from Alexis Sanchez's free kick in the first half.
That goal seemed to wake Everton up, and Ronald Koeman's side managed to disrupt Arsenal's normally flowing attacking game after stepping up their aggression.
"It was a very physical game, we faced many challenges and we lost as well some balls that we are not used to, and I think it disturbed our game," Wenger told BT Sport.