Match ends, Swansea City 2, Manchester United 1.
- Swansea complete first league double over United
- Gomis deflected goal seals win for Swans
- United lose for second time in 20 games
- Van Persie leaves stadium on crutches
Manchester United suffered only their second Premier League defeat since November as Bafetimbi Gomis's second-half goal gave Swansea victory.
Ander Herrera's low strike put United ahead, but the hosts responded immediately as Ki Sung-yueng flicked in from Jonjo Shelvey's cross.
Louis van Gaal's side dominated the second period but failed to score.
Shelvey's 73rd-minute shot deflected off Gomis to give the Swans a first league double over United.
Defeat means United drop to fourth place in the Premier League - Arsenal leapfrogging them by beating Crystal Palace - and hampers their hopes of making an instant return to the Champions League after failing to qualify for Europe last season.
Swansea won 2-1 at Old Trafford on the opening day of the season to ruin Van Gaal's first competitive match as United boss.
And the Welsh club pained the Dutchman again by inflicting only a second defeat on United in 20 matches across all competitions.
The Red Devils' misery was compounded by the sight of Robin van Persie leaving the Liberty Stadium on crutches, with a protective boot around his right ankle after suffering a late injury.
The Netherlands striker had been recalled from injury as United made three changes from their FA Cup win at Preston.
There was a more radical alteration from Swansea, as manager Garry Monk switched to a midfield diamond for the first time.
|Swansea put two league goals past Manchester United at home for the first time since January 1982|
|Ki Sung-yeung has scored in back-to-back appearances at the Liberty Stadium for Swansea|
And it was the hosts who made the stronger start.
Gomis had managed only one league goal before this match, but the France international striker could have scored twice in the opening 10 minutes.
His header from a Gylfi Sigurdsson corner was cleared off the line by Herrera, while he nodded over from Ki's flick on moments later.
United threatened sporadically as Van Persie's close-range effort grazed the crossbar and Wayne Rooney had his first shot on target of 2015, albeit a weak effort easily held by Lukasz Fabianski.
When the visitors' attacking talent finally clicked, they took the lead in fine fashion.
After Luke Shaw's burst down the left wing, a neat exchange of passes between Wayne Rooney and Angel Di Maria set up Herrera, whose low drive went in off the post.
But the lead lasted less than two minutes, as Shelvey's excellent cross was guided in by Ki.
After an open, fluid first half in which both sides pushed forward, United sought to control the contest after the interval by dominating possession.
Swansea dropped deeper as a result, seemingly inviting pressure, and there were scares for the hosts such as Marcos Rojo's missed free header.
Their resilience was rewarded with 15 minutes left, as Shelvey's 25-yard shot deflected off Gomis to seal Swansea's second win of the season over United.
- 6WilliamsBooked at 88mins
- 4Ki Sung-yueng
- 23G SigurdssonSubstituted forMonteroat 74'minutes
- 8ShelveyBooked at 90minsSubstituted forAmatat 90+4'minutes
- 1de Gea
- 33McNairSubstituted forA Valenciaat 45'minutes
- 4JonesBooked at 48mins
- 5RojoBooked at 88mins
- 3ShawSubstituted forYoungat 58'minutesBooked at 84mins
- 7Di MaríaSubstituted forMataat 79'minutes
- 31FellainiBooked at 45mins
- 20van Persie
- 25A Valencia
- Neil Swarbrick
- Shots on Target
Second Half ends, Swansea City 2, Manchester United 1.
Attempt blocked. Daley Blind (Manchester United) left footed shot from outside the box is blocked. Assisted by Juan Mata.
Substitution, Swansea City. Jordi Amat replaces Jonjo Shelvey.
Marouane Fellaini (Manchester United) wins a free kick in the defensive half.
Foul by Jefferson Montero (Swansea City).
Attempt blocked. Wayne Routledge (Swansea City) left footed shot from the centre of the box is blocked.
Jonjo Shelvey (Swansea City) is shown the yellow card for a bad foul.
Phil Jones (Manchester United) wins a free kick in the attacking half.
Foul by Jonjo Shelvey (Swansea City).
Offside, Manchester United. Phil Jones tries a through ball, but Marouane Fellaini is caught offside.
Marcos Rojo (Manchester United) is shown the yellow card for a bad foul.
Foul by Marcos Rojo (Manchester United).
Lukasz Fabianski (Swansea City) wins a free kick in the defensive half.
Ashley Williams (Swansea City) is shown the yellow card for a bad foul.
Marouane Fellaini (Manchester United) wins a free kick in the attacking half.
Foul by Ashley Williams (Swansea City).
Attempt saved. Bafétimbi Gomis (Swansea City) right footed shot from the right side of the box is saved in the centre of the goal. Assisted by Wayne Routledge.
Foul by Marouane Fellaini (Manchester United).
Jack Cork (Swansea City) wins a free kick on the right wing.