Arsenal are now level with Manchester City at the top of the Premier League table.
The Gunners beat Everton 2-0 at the Emirates to keep their perfect home record intact.
Ezri Konsa scored his first goal for the champions, forcing the ball into the net after a corner kick.
Arsenal had to wait until the second half to double their lead, with Gabriel Magalhaes heading in Ben White's cross.
In the early kick-off, City lost for the first time this season, with Aston Villa claiming a 2-1 win at Villa Park.
Nicolas Jackson scored either side of Erling Haaland's goal to give the hosts maximum points.
City and Arsenal both have 21 points, with Enzo Maresca's men only ahead on goal difference.
EPL table: Arsenal now joint top with Man City after victory over Everton