Everton allowed a two-goal lead to slip away for the second week in a row as Ollie Watkins scored twice and Jhon Duran scored a stunning goal to help Aston Villa come from behind and win 3-2.
The Toffees were hoping to recover from their previous collapse against Bournemouth and were leading by two goals again thanks to goals from Dwight McNeil and Dominic Calvert-Lewin.
Villa were facing the possibility of a second consecutive home defeat, but Watkins scored his first goal of the season to reduce the deficit before halftime.
Everton fought hard to maintain their lead in the second half, but Watkins equalized with half an hour remaining before Duran's long-range goal secured the victory.
In the early stages, Unai Emery's team was dominant, and Morgan Rogers' long-range shot was easily saved by goalkeeper Jordan Pickford.
Despite being against the run of play, the visitors took the lead when former Everton player Amadou Onana lost possession, allowing McNeil to score.
Everton extended their lead in the 27th minute with a goal from Calvert-Lewin.
McNeil assisted Calvert-Lewin with a free-kick, and the striker headed the ball into the net from close range.
Villa pulled one goal back just before halftime with Watkins scoring from a cross by another former Everton player, Lucas Digne.
Rogers continued to challenge Pickford, but the goalkeeper denied him a second goal.
Onana was substituted at halftime, and Villa improved their attack in search of an equalizer.
Villa threatened early in the second half, with Rogers being stopped by Pickford before Ramsey's attempt was blocked by Garner.
After missing a chance to seal the game, Everton saw their lead slip away once more.
A long pass intended for Digne was intercepted by Harrison, but it fell to Watkins who scored to level the game.
Watkins could have scored more goals, missing opportunities set up by Rogers and firing wide from a close range.
Aston Villa took the lead with a fantastic goal by Duran from 30 yards out, marking his third goal coming off the bench this season.
Forced to push forward, Everton almost equalized right away, but Calvert-Lewin's effort hit the crossbar as Sean Dyche's team suffered their fourth consecutive league defeat, a first since 1958.