Swansea City staged a stirring comeback to inflict a first defeat of the season on Manchester United.
After the Swans had edged a goalless first half, United took the lead early in the second as Luke Shaw's marauding run and cross set up Juan Mata to blast in from close range.
Andre Ayew headed the hosts level after a swift counter-attack as United conceded their first league goal of the season.
Ayew then provided a marvellous pass for Bafetimbi Gomis, whose shot squirmed under Sergio Romero to give Swansea a third straight win against United.
Having done the double against United for the first time last season, Garry Monk's side became only the sixth team to claim three successive league victories against the Red Devils.
For visiting manager Louis van Gaal, a first loss of the campaign was a miserable way to mark his 50th game in charge.

United's defensive fragility

With both teams protecting unbeaten starts to the season, there was a bristling intensity to the early exchanges.
United had not conceded in their opening three matches, but that record was under threat as Swansea pressed with chances for Gomis and Gylfi Sigurdsson.
Gylfi Sigurdsson shoots wide for Swansea
Swansea had just 37% of the possession in the first half but came close through Gylfi Sigurdsson
Daley Blind, a midfielder currently playing at centre-back, offered little resistance as Gomis skipped past him and his central defensive colleague Chris Smalling before clipping the post with a delicate low shot.
Those fragilities were eventually exposed when Ayew and Gomis took advantage of slack marking and dubious goalkeeping to put Swansea ahead.

Monk's masterstroke

There may have been a few eyebrows raised when, with his team trailing after 57 minutes, Monk replaced winger Wayne Routledge with midfielder Ki Sung-yueng.
But the switch to a midfield diamond was vindicated after just four minutes as Ashley Williams strode out of defence and freed Sigurdsson, whose precise cross found Ayew for Swansea's equaliser.
The hosts were ahead four minutes later, as Ayew's artful through-ball with the outside of his foot found Gomis, whose low finish beyond Romero sent the Liberty Stadium crowd wild and gave Monk the satisfaction of a tactical alteration paying off in style.

Van Gaal's midfield headache

United's two changes from the midweek Champions League win at Club Brugge saw Van Gaal recall two of his highest-profile summer signings, Bastian Schweinsteiger and Morgan Schneiderlin.
That pushed fellow central midfielder Ander Herrera into a more advanced role behind striker Wayne Rooney, but United struggled for fluency.
The one positive was another bright display from Mata but, playing in his unfavoured position wide on the right, he was substituted after 70 minutes.
Touch maps for Wayne Rooney, Diego Costa and Christian Benteke
Wayne Rooney (left) had half the number of touches in and around the penalty box that Chelsea striker Diego Costa (centre) and Liverpool forward Christian Benteke (right) managed in their teams' games this weekend

Man of the match: Andre Ayew

Andre Ayew
The tireless Ghanaian forward was a constant menace, taking his goal well and providing a superb pass for Gomis's winner

Post-match reaction:

Swansea manager Garry Monk: "It was an amazing atmosphere. The first half, Manchester United played very well and made it very difficult for us.
"We showed our character. I don't think we were at our best, but we were organised and kept our shape.
"They were causing us problems centrally. I changed it with four midfielders inside and that allowed us to get into the game."
Manchester United manager Louis van Gaal: "We controlled the game for 85 minutes but we lost in five minutes and that cannot happen.
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Van Gaal believes his side were unlucky to lose
"They changed the shape and we had to be compact. We forgot that maybe because we are too dominant. We have to learn from that.
"First you have to create chances, with scoring goals you need luck that we don't have at the moment.
"I have enjoyed our football but you need the result and we lost again. All the players were very motivated to beat them."

Pundit analysis

Former Arsenal striker Ian Wright on BBC Radio 5 live: "I haven't got a clue what Van Gaal is trying to do. What's their system? Surely Manchester United have got to play with a bit more pace and thrust and tempo. They seemed desperate."