Chelsea went to Goodison Park hoping to bounce back from a disappointing midweek defeat to Manchester United, but what Mauricio Pochettino got from his players was another toothless display.
The Blues dominated possession all afternoon, yet failed to create clear-cut chances when they reached the Everton penalty area.
Cole Palmer forced Jordan Pickford into two good saves with long-range efforts either side of half-time, but it was the hosts that broke the deadlock when Abdoulaye Doucoure slotted home after Robert Sanchez had saved well from Dominic Calvert-Lewin.
The goal - a breakaway through the middle - exposed the soft underbelly that has plagued Chelsea all season. Yet another injury for captain Reece James - as well as No.1 goalkeeper Sanchez - added to Chelsea's woes.
Pochettino's side failed to respond in the 35 minutes that followed, and Lewis Dobbin's late strike condemned them to a seventh league defeat of the campaign.
GOAL rates Chelsea's players from Goodison Park...