Angelo Ogbonna's header earned West Ham United a 1-0 victory that ended Everton's perfect home record this season and moved them above the Toffees into seventh place.
In an evenly contested first half, Alex Iwobi squandered an opportunity to put Everton ahead from close range following Abdoulaye Doucoure's 22nd-minute cross.
After the break, Salomon Rondon headed agonisingly wide for Everton while West Ham's Pablo Fornals curled his shot just off target as the teams traded chances.
But with 16 minutes remaining, West Ham took the lead when a superb corner kick from Jarrod Bowen was headed in by Ogbonna from close range.
West Ham's victory takes them to 14 points, ahead of eighth-placed Everton on goal difference.
Everton: 23 Oct v Watford (H)
West Ham: 24 Oct v Spurs (H)
Referee: Stuart Attwell. Assistants: Harry Lennard, Simon Long. Fourth official: Martin Atkinson. VAR: Paul Tierney. Assistant VAR: Adam Nunn.