Everton delivered an extraordinary result at Old Trafford, holding on for a rare away win despite Idrissa Gueye being sent off for striking team-mate Michael Keane just 13 minutes into the match.
Gueye reacted angrily to Keane’s comments while defending a set-piece, moving toward the defender and slapping him on the cheek.
Jordan Pickford intervened to restrain the midfielder, but referee Tony Harrington immediately produced a red card.
Keane, furious, gestured for Gueye to leave the pitch. The confrontation evoked memories of the infamous Bowyer-Dyer incident at Newcastle.
The dismissal added to an already chaotic start for Everton, who had lost captain Seamus Coleman to injury only minutes earlier in his first league start of the season.
Dewsbury-Hall provides the breakthrough
Against the run of expectation and at a venue where Everton had won only once since 1992, Kiernan Dewsbury-Hall produced a moment of quality.
The midfielder drove forward to the edge of the box and curled a superb effort beyond Senne Lammens to give the visitors a shock lead.
United dominate but Everton stand strong
Manchester United pushed relentlessly for an equaliser, aware that a win would have taken them up to fifth. Despite constant pressure, they failed to break through a resolute Everton defence that protected their lead with disciplined, last-ditch organisation.
In doing so, Everton became the first Premier League side to win at Old Trafford after having a player sent off, a historic and improbable achievement.
The night also marked a personal milestone for David Moyes, who secured his first Premier League victory at Old Trafford as an opposing manager, adding evening more excitiment for the manager in an already extraordinary outcome.