Brighton secured English Premier League football for another season by beating Manchester United 1-0 on Friday as Pascal Gross scored early in the second half and the hosts ended a seven-match winless run.
United arrived on the south coast knowing a win would all-but seal second place, but a poor effort led to its first loss to Brighton since 1982.
Visiting coach Jose Mourinho made six changes as Matteo Darmian, Marcos Rojo, Marouane Fellaini, Juan Mata, Marcus Rashford and Anthony Martial came in for Victor Lindelof, Antonio Valencia, Ander Herrera, Jesse Lingard, the injured Romelu Lukaku, and Alexis Sanchez, who reportedly did not travel.
"The players that replace others, they didn't perform at a good level," Mourinho said. "So maybe now you understand why some players play more than others."
Fellaini had the ball in the net after only three minutes but he was offside when he turned home Rashford's free kick.
That was about as good as it got in a horribly disjointed display from United.
Brighton broke the deadlock 12 minutes after the interval.
Jose Izqueirdo skipped past Matteo Darmian and stood a cross up toward the far post. United goalkeeper David De Gea pushed the ball onto the head of Gross and, although Marcos Rojo hooked it clear from underneath the crossbar, goal-line technology confirmed it crossed the line.
United belatedly rallied but Maty Ryan saved from Rashford and Jesse Lingard fired wide as Brighton held out.