Manchester United conceded three first-half goals as they slumped to a 3-2 defeat at Brighton in a game illuminated by a superb goal from Seagulls striker Glenn Murray.
Murray's outstanding flick opened the scoring, Shane Duffy quickly adding a second, and although Romelu Lukaku pulled one back, Pascal Gross scored a penalty before half-time to restore the two-goal lead.
Paul Pogba's penalty in second-half stoppage time was too little, too late for disjointed United.
Brighton began on the front foot, Solly March's cross cleared by Pogba and then Gross attempting to flick on an Anthony Knockaert delivery only for United to get it away.
Pogba spread the play to Anthony Martial on the left, his low ball into the area cleared as United hit back, and Brighton sprang forward again when March's cross was held by David De Gea.
United had a good chance to take the lead after 10 minutes when, after Lewis Dunk had given the ball away to Lukaku, Pogba played the striker in only for him to fizz a low shot past the near post.
Brighton captain Dunk was struggling after his challenge with Lukaku, with home boss Chris Hughton prepared to bring on Leon Balogun in his place.
A clumsy Luke Shaw challenge on Knockaert gave Brighton a free kick on halfway but, when a long ball forward was headed down, an offside flag stopped Murray.
Dunk was eventually substituted after 20 minutes, and soon afterwards Knockaert had half a chance when he latched on to a speculative ball but sliced his attempt well wide.
But after 25 minutes Brighton broke through, March producing another dangerous cross from the left and Murray's sublime flick steering the ball beyond De Gea and into the corner.
Two minutes later they doubled their lead when, after one ball had fizzed across the box, United failed to deal with the second and Duffy turned and fired into the corner.
Pogba thumped a speculative effort well over with United struggling to make any headway against the well-organised home side -- but after 34 minutes they found a way back, Shaw's bouncing, deflected ball into the area glanced home by Lukaku.
Knockaert was brought down 25 yards out, getting up to curl the free kick over the bar, but three minutes from the break Brighton had a penalty when Eric Bailly fouled Gross as he broke through -- and the Brighton man blasted the kick in off De Gea.
United were increasingly ragged, Martial booked for a foul on Knockaert after they had given the ball away near their own area, and Jose Mourinho made a double change at the break, bringing on Marcus Rashford for Juan Mata and Jesse Lingard for Andreas Pereira.
But the defence that had struggled so badly in the first half remained unchanged and both March and Davy Propper were within a whisker of winning the ball back as Bailly dawdled near his own area.
Pogba headed well wide from a deep delivery as United sought a way back into things on the south coast, but Brighton were happy to sit deep with their visitors showing little in the way of imagination.
On the hour, Rashford's dangerous header across goal was well dealt with by Duffy before Mourinho made his final change, Marouane Fellaini coming on for Martial as United finally began to put some pressure on their hosts.
Goal scorer Murray was booked for a challenge on Lindelof, much to the disgust of the home fans, but United were struggling to find any sort of threatening final ball, instead playing hopeful passes forward that were easily dealt with by the Brighton defence.
Pogba tried a different approach, hitting a fine shot from distance that produced an equally good response from keeper Mat Ryan, who dived to push it away one-handed.
Ryan was hurt in a collision with teammate Duffy as both tried to deal with another looping United cross, but the Australia international was able to continue.
Hughton made a late change, taking off Gross and replacing him with Beram Kayal and then replacing Murray with Jurgen Locadia.
Pogba scored a late, late penalty after Duffy's foul on Fellaini, but the Seagulls saw out the remaining time to beat United at home for the second successive season.