Arsenal fell to Burnley 1-0 in a mistake-riddled match that saw Granit Xhaka sent off in 58th minute for violent conduct and Pierre-Emerick Aubameyang net an own-goal.
The shock loss at Emirates will add more pressure to Mikel Arteta, whose 15th-place side now flirts with the relegation zone on 13 points.
After going into the break, the Gunners unraveled after going to 10 men when Xhaka was boked for grabbing Dwight McNeil by the neck.
Despite the red card, Arsenal saw Aubameyang produce some good scoring chances only to be hit with bad luck in the 73rd minute when the captain flicked the ball into his net from a set-piece.
Burnley jump out of the bottom three with the win, sitting in the 17th place above Fulham by one point.