Arsenal missed their chance to go back to the top of the Premier League after being forced to play with 10 men for much of the game against London rivals Chelsea on Sunday.
Defender Per Mertesacker was sent off in the first 20 minutes for a foul on Diego Costa, who scored the only goal shortly afterwards from a cross by Branislav Ivanovic.
The result preserved the defending champions' unbeaten record under experienced Dutchman Guus Hiddink, who took over as interim manager last month following Jose Mourinho's sacking.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
Chelsea moved up to 13th, while Arsenal were left in third place, level on points with Manchester City but three behind leaders Leicester City.
(Reporting by Steve Tongue, editing by Alan Baldwin)
