Arsenal had a chance to reextend their lead atop of the Premier League to eight points on Sunday.
However, a James Tarkowski header was enough to hand Everton a win in their first game under Sean Dyche.
Manchester City can now close the gap on the Gunners to two points with a win on Sunday, though Arsenal still have one game in hand.
Following the Everton loss, Mikel Arteta has been full of praise for his players.
Asked whether his players were feeling any pressure, Arteta said: “No, I don’t think so, we’ve played a lot of games this season like that already.
“But credit to them, this is what they train every single day. You have to defend really well to get your control and earn the right to play. For moments we did it and in other moments we didn’t do it well enough to dominate in the game.
“In the last 10 or 15 minutes, particularly after we made the changes, we started to give away a lot of free-kicks and a lot of rash decisions.
“Which is exactly what they want - slow the game down, do everything really long, play long into your line and don’t play a lot. We haven’t managed that well enough.
“I want the team to know how much I love them. I love them much more now than three hours ago, a week ago, a month ago, three months ago.
“It’s very easy to be next to the players when they’re winning and performing. These are the moments when I love my players more and my staff more and we’re going to stay together.
“This journey is going to be difficult and challenging and there’s going to be big stones in the middle and we have to overcome that. Now we have to prepare the week really well to get to Saturday with the right emotional spirit to beat Brentford.”