A dominant Everton inflicted a sixth defeat in eight games on Manchester United to dent their hopes of a top-four Premier League finish.
Gylfi Sigurdsson and Lucas Digne scored stunning long-range goals after Richarlison’s acrobatic opener at Goodison Park.
Substitute Theo Walcott completed the rout with a guided finish.
A lacklustre United, who were knocked out of the Champions League by Barcelona on Tuesday, were bereft of ideas and their only shot on target came in the 86th minute.
Marcus Rashford spurned their best chance when he got behind the Everton defence and his lob sailed over Jordan Pickford’s crossbar.
Victory lifted Everton to seventh in the table, which could deliver European football next season, while United remain sixth.
They are two points behind fourth-placed Arsenal, who host Crystal Palace at 16:00 BST on Sunday.