Arsenal centre-back David Luiz was sent off in a one-man horror show at Manchester City after giving away the first goal in the game shortly after being introduced to the action as a substitute.
Luiz replaced the injured Pablo Mari in the Gunners defence 24 minutes into the first half, and his error gifted City the lead just before the interval.
Raheem Sterling got in behind the Brazilian after he made a hash of controlling a through ball, before finishing expertly past Bernd Leno in the Arsenal net to fire the home side in front.