At the Emirates Stadium, fifth-placed Arsenal closed the gap on fourth-placed Chelsea to three points in the race to qualify for the Champions League with a 2-0 win.
Unai Emery’s team had lost three of their last six league games, sparking the first criticism of their Spanish manager.
But they tore into London rivals Chelsea, opening the scoring in the 14th minute.
Hector Bellerin’s cross found Alexandre Lacazette and the French striker took a touch before smashing a sublime strike past Kepa Arrizabalaga from a tight angle.
The Gunners increased their lead in the 38th minute when Laurent Koscielny mistimed his attempted header, only to see the ball bounce off his shoulder and loop into the net.
Arsenal’s Hector Bellerin was stretchered off in the second half, but spluttering Chelsea have now won only two of their last five matches.
“It was a big result. We wanted to do a special moment in this derby. Chelsea were six points ahead, so it helps us. We can be optimistic,” Emery said.