Chelsea suffered a third loss in four Premier League games on Saturday, opening Week 16 with a 3-1 defeat at Goodison Park. Duncan Ferguson made a triumphant start as interim Toffees manager.
Dominic Calvert-Lewin scored twice for the home side following a Richarlison opener, and former Toffee Ferguson ended Everton's run of three losses in a row with a turn-up against the odds.
Jose Mourinho's Tottenham Hotspur climbed to fifth and within six points of the Blues in fourth after they demolished Burnley 5-0 at home thanks, in part, to a Harry Kane brace.
Leaders Liverpool temporarily restored an 11-point cushion at the top of the table following a convincing victory away to Bournemouth, where Mohamed Salah scored and assisted in a 3-0 win.