A superb first-half strike by Crystal Palace defender Joachim Andersen condemned Manchester United to a second successive Premier League home defeat on Saturday.
The match at Old Trafford finished 1-0 and marked the second meeting for both sides in five days, with United comfortably winning 3-0 in the Carabao Cup on Tuesday.
But this time around, Palace were the better side as Erik ten Hag's side struggled to create many clear openings.
The closest United came to scoring was when a Rasmus Hojlund effort cleared off the line by Tyrick Mitchell in the 12th minute.
Soon afterwards, Andersen superbly drove a first-time effort into the top corner after a free-kick.
The goal forced United to push for an equaliser but Palace held onto the slender lead, with goalkeeper Sam Johnstone making two crucial saves in the second half to preserve Palace's lead, first pushing over Bruno Fernandes' long-range effort before keeping out Hojlund's bullet header.
The win means Palace climb over United into ninth, while United drop to 10th.