Premier League leaders Chelsea beat London rivals Arsenal 2-1 with goals from Spaniards Fernando Torres and Juan Mata to maintain their unbeaten start to the season while handing Arsenal their first defeat.
Both Chelsea goals came as a result of Mata free kicks and poor Arsenal defending with Torres out-muscling Laurent Koscielny to volley the European champions ahead at the Emirates Stadium after 20 minutes for his third league goal of the season.
Gervinho equalised for Arsenal three minutes before the break when he turned crisply and fired into the roof of the net for his fourth goal of the campaign.
Chelsea, who started with skipper John Terry as he mulls an appeal over a four-game ban for racist abuse, regained the lead after 53 minutes when Mata's free kick eluded everyone before clipping Koscielny and flying in past keeper Vito Mannone.
The victory lifted Chelsea four points clear at the top, at least until the rest of the programme later on Saturday.