Arsenal failed to maintain their seven-point gap at the top of the Premier League table, after they lost 3-2 to Manchester United on Sunday evening.
The Gunners came into the game, knowing that their title rivals Manchester City and Aston Villa both won their fixtures this weekend.
City beat Wolves 2-0 at home, while Villa won 2-0 at Newcastle United earlier today.
Arsenal took the lead in the first half through a Lisandro Martinez own goal, before Bryan Mbeumo pounced on a defensive error to make it 1-1 before half time.
Patrick Dorgu put the Red Devils ahead with a sensational effort from range.
And although Mikel Merino made it 2-2 late on, there was time for Matheus Cunha to lash in a winner.
Mikel Arteta’s men are now only four points clear at the top of the table, while United now sit in fourth place.