Manchester United suffered a fourth defeat in five games at Old Trafford as Brighton claimed an impressive 3-1 victory.
Yankuba Minteh gave the visitors the lead in the fifth minute before Bruno Fernandes equalized from the penalty spot.
United were coming off a thrilling comeback victory over Southampton this week, but there were no heroics this time.
Second half goals from Kaoru Mitoma and Georginio Rutter saw the Seagulls take all three points, leaving the Red Devils in 13th place.
Mail Sport's NATHAN SALT was on hand to take a look at both sets of players…
Brighton beat Manchester United 3-1 at Old Trafford in the Premier League on Sunday
MANCHESTER UNITED (3-4-2-1)
André Onana – 5
He hesitated when perhaps he needed to be more decisive and come for Yankuba Minteh's cross from the right that led to the second goal.
He was let down by those in front of him when the first goal came, but made a colossal mistake by spilling a cross that allowed Georginio Rutter to make it 3-1.
Matthjis de Ligt – 5
He was left on his knees staring at the sky when he completely misjudged where Rutter was and reacted too late to rectify it once Onana spilled the cross.
He was solid for long periods, but his positional awareness can often let him down at crucial moments.
Harry Maguire – 5.5
He misjudged the defensive line by placing Kaoru Mitoma on the wing for the first goal, but soon got into rhythm.
Amorim likes to protect his lack of pace with faster players alongside him and although he coached Danny Welbeck well, both sides of him lost their clashes and he had plenty to do.
Harry Maguire had his work cut out for him as those on his side lost their battles.
Leny Yoro – 6
He was moved to the left side of the back three after a difficult night at right centre-back against Southampton on Thursday.
As on Thursday night, he received limited protection or help from his full-back and remains isolated. One of the few players who progressed when he had the ball, which will please his coach.
Noussair Mazraoui – 4
He completely lost sight of Mitoma as he spun back with ease before teeing up Yakumba Minteh for a tap-in for the first match and then lost track of Mitoma for the second, with the Japanese converting down the stretch. His worst game since he arrived in the summer by far.
Kobbie Mainoo – 6
He remains clean and tidy, but United need him to put a greater stamp on the games if they are to return to the upper echelons of the table. He made the best of his battle with Carlos Baleba, so he deserves credit.
Manuel Ugarte – 5
He was left exposed on Yasin Ayari's breakaway en route to Brighton's second goal and, as he did against Southampton, found it difficult to establish much dominance in the midfield battle.
Diogo Dalot – 6
Returning to the team after his suspension on Thursday, he found life very difficult opposite Minteh and as a result found it difficult to offer any kind of significant presence in the attacking phases of the game.
He made a crucial block to deny Danny Welbeck a goal towards the end of the first half.
Bruno Fernandez – 6.5
He was the coolest man in the stadium when he sent Brighton goalkeeper Bart Verbruggen the wrong way from the penalty spot to level the match. Thereafter, he cut a frustrated figure as his final balls flew over or wide.
Bruno Fernandes was not wrong with his penalty, but he seemed frustrated throughout.
Amad Diallo – 7
Once again, United's most dangerous and dynamic player, but this time not even he could perform the rescue act necessary to avoid United's blushes.
His directness keeps the full-backs honest, but shouldering sole creative responsibility isn't going to work forever. He needs his teammates to step up or he'll be eliminated from these games.
Joshua Zirkzee – 6
He deserves an immense amount of credit for not allowing his humiliating first-half substitution against Newcastle United to define him in a United shirt.
It was his annoyance that earned United the penalty when Carlos Baleba tackled him to the ground. He offered a useful physique in both frames, even in defeat.
Joshua Zirkzee offered useful physicality in both areas and won his team the penalty.
MANAGER: Ruben Amorim – 5
He never goes up or down too much after games and that is perhaps because he knows the rollercoaster nature of this job and this club.
He played with his team here but couldn't find the answer to limit Mitoma and Minteh's influence on the wings. That's where this game was won and lost.
SUBSTITUTES
Toby Collyer (by Manuel Ugarte, 64) – 5
Alejandro Garnacho (for Kobbie Mainoo, 64) – 6
Rasmus Hojlund (substitute for Joshua Zirkzee, 84)
Antonio (by Noussair Mazraoui, 84)
BRIGHTON (4-2-3-1)
Consumers 6; Veltman 6.5, Van Hecke 6, Dunk 7, Estupinan 5 (Lamptey 84); Baleba 6, Ayari 6.5; Minteh 7.5 (March 69, 6), Peter 7, Mitoma 8.5; Welbeck 6.5 (Rutter 69, 7)