Two late goals in as minutes by Tammy Abraham sealed a derby victory for Chelsea.
Thiago Silva put the Blues ahead by heading home Mason Mount’s 10th-minute corner.
There were some anxious moments for Frank Lampard’s side, who had lost their previous two matches.
But Abraham diverted Timo Werner’s scuffed shot into the net and then scored from a tight angle after Lukasz Fabianski had pushed out Mount’s cross.
Chelsea are back up to fifth and almost scored again in the final minute when Werner fired against the crossbar.
Chelsea: Mendy, Azpilicueta, Zouma, Silva, Chilwell (Emerson 10), Kante, Jorginho (Kovacic 66), Werner, Mount, Pulisic (Havertz 84), Abraham.
Subs not used: Kepa, Rudiger, Christensen, Giroud, Hudson-Odoi, Gilmour.