Swansea City recorded their first league double over Manchester United as the latter dropped to fourth position following defeat at the Liberty Stadium on Saturday.
Ander Herrera’s powerful drive put the ‘Red Devils’ ahead after making a goal-line clearance of Bafetimbi Gomis header early on in the first half.
But the visitors’ lead lasted only two minutes as Ki-Sung-yeung steered in from Jonjo Shelvey’s left-wing cross to restore parity, leaving both side with an arduous task in the second half.
Swansea finished off the job when Shelvey’s deflected shot from 25 yards blazed past a wrong-footed goalkeeper David De Gea in the 73rd minute.
Swansea manager Garry Monk resorted to a diamond formation, with Iceland midfielder Gylfi Siggurdson back from a three-match suspension, making two changes from the 2-0 defeat to West Bromwich Albion as Wayne Routledge was named in place of Nathan Dyer and employed right behind striker Gomis.
Robin van Persie returned to Louis van Gaal’s starting XI after missing the FA Cup win at Deepdale with a minor knock. Teenager Paddy McNair and Phil Jones also came in for Antonio Valencia and Chris Smallings in the defence.
Van Gaal was left staring at an unreal reality after a 2-1 defeat by the South Wales outfit in his first home match as United boss five months ago, but after managing to real in 34 points from their last 15 matches- more than any other team in the league during that time- it was another bad day at work for the Dutch.
The former Ajax, Barcelona and Bayern Munich coach had claimed United were the best in the top flight on current form after losing only once in 19 games in all competitions but those seeming form could not help keep their top-4 ambitions on track.
Marcos Rojo almost gifted Swansea an early opener when his poor pass set up Sigurdsson, whose shot was blocked for a corner. The Icelandic midfielder sent the ensuing cross in and Gomis lost his marker, McNair, to thump a header only for Herrera to clear off the line with his outstretched legs.
Goalkeeper Lukasz Fabianski failed to gather Angel Di Maria’s corner, allowing Van Persie to collect the ball and fire onto the crossbar in an end-to-end start at the Liberty Stadium.
Gomis slipped Phil Jones to set up a shooting opportunity for Wayne Routledge, but De Gea was equal to the task.
United claimed the opening goal with some fine counter, which saw Wayne Rooney finding Di Maria and the Argentine set up Herrera for a precise finish into the corner.
Swansea responded instantly with a Shelvey delivery from the left finding Ki, who like in the reverse at Old Trafford, scored by getting across Luke Shaw and sweeping the ball home.
De Gea was in hand to deny Ki a second soon after the restart, when the South Korean released from range after a well-timed run.
United saw more of the ball after a couple of substitutions but could not make a goal of them, with Van Persie firing into the side netting on his more favoured left foot.
Rojo headed over a Di Maria corner and Van Persie could only scuff his attempt wide under pressure after Rooney dinked the ball over the top of Swansea defence to him.
Swansea struck against the run of play in the 73rd minute when Shelvey’s powerful strike beat De Gea via a slight deflection off Gomis’ head.
Gomis forced another save from De Gea in the final exchanges as United failed in their effort to snatch a late equaliser.