New Everton boss Sean Dyche's reign began with a shock 1-0 victory over Premier League leaders Arsenal as James Tarkowski's second-half header saw the Toffees win their first game since October and move out of the relegation zone on Saturday.
The defeat left Arsenal with a five-point lead over second-placed Manchester City, who visit Tottenham Hotspur on Sunday.
Everton looked a much-improved unit in Dyche's first game in charge after replacing Frank Lampard and they troubled Arsenal throughout, coming close to opening the scoring in the first half through Dominic Calvert-Lewin and Abdoulaye Doucoure.
Tarkowski finally broke the deadlock for the hosts on the hour mark with a powerful header from a corner by fellow former Burnley man Dwight McNeil which flew past Aaron Ramsdale.
Arsenal did pose problems, with Bukayo Saka forcing a goal-line clearance from Tarkowski after a volley in the first half and Eddie Nketiah blasting an effort over from close range.
Deadline day signing Jorginho made his Gunners debut a minute before Everton's goal but could not do enough to change his side's fortunes.
Everton, who had only been separated from bottom spot by goal difference, are now 17th, a point above the drop zone.