Alex Iwobi snatched a winner deep into injury time to give Fulham their first victory against Manchester United at Old Trafford since 2003.
The 2-1 win was only the Londoners' second at the stadium since 1963 and brought to a halt United's run of four straight Premier League victories.
Erik ten Hag's side were without injured Danish striker Rasmus Hojlund, who had scored in six consecutive games.
Academy graduate Omari Forson, 19, was brought in for his first start in attack, with Marcus Rashford playing as the striker. But United looked toothless going forward and it was Fulham who drew first blood.
They made the breakthrough after 65 minutes when Nigerian defender Calvin Bassey swept the ball in from a corner.
Harry Maguire thought he had rescued a point for the hosts when he equalised in the 89th minute when Bruno Fernandes’ cross was pushed out by Fulham keeper Bernd Leno and the Englishman lashed the loose ball home.
But nine minutes into stoppage time, Iwobi applied the finishing touch to a sweeping counter-attack and Fulham took all three points.
The win ended a run of 11 away matches without a victory for the Cottagers and inflicted a major blow to United's hopes of clinching a Champions League place. They now sit eight points adrift of Aston Villa in fourth place.
Fulham matchwinner Alex Iwobi said afterwards: "I'm over the moon right now to come back into the team and get the win here – there is no better feeling.
"We feel we performed really well and have been performing really well recently, it is just about getting the results."
United scorer Maguire admitted: "Overall on the balance of play we didn't do enough in the first 60 minutes or so, we started the game not great.
"We were probably naive in the end by throwing too many bodies forward and getting done on the counter attack.
"We've been on a good run of form and came into the game we were confident."
Aston Villa, meanwhile, consolidated fourth place as they beat Nottingham Forest 4-2.
Ollie Watkins gave Villa an early lead with a tap-in and Douglas Luiz made it 2-0 on the half-hour mark.
Forest fell further behind six minutes before the break when Luiz headed in his second.
Moussa Niakhate then pulled a goal back for Forest in first-half stoppage-time following a corner.
Forest further reduced the deficit three minutes into the second half when Morgan Gibbs-White broke to clip the ball over Villa keeper Emi Martinez.
But Villa restored their advantage in the 61st minute when Forest were caught playing out from the back and Leon Bailey slotted the ball in after Watkins’ effort was saved.
Villa manager Unai Emery told Sky Sports after the match: "I'm very happy. A fantastic first half – we conceded one corner, one goal, but we dominated the match.
"The second half, we were nervous after the goal, but again we reacted very well. Douglas Luiz was very important, he controlled the ball and we controlled the game."
New Crystal Palace manager Oliver Glasner got off to the perfect start with a 3-0 win over 10-man Burnley at Selhurst Park.
The visitors were down to 10 men in the 35th minute when Josh Brownhill was shown a straight red card for bringing down Palace midfielder Jefferson Lerma.
Chris Richards headed Palace in front after 68 minutes, the American’s first goal for the club, before Jordan Ayew swiftly added another.
Jean-Philippe Mateta wrapped things up with a third from the penalty spot with 11 minutes left.
Burnley, who remain deep in relegation trouble, saw a late goal from David Fofana ruled out for offside in the build-up.
Brighton captain Lewis Dunk struck a stoppage-time equaliser to snatch a 1-1 draw against Everton at the Amex Stadium.
Defender Jarrad Branthwaite put Everton ahead with 17 minutes left when he rifled the ball into the top-right corner following a free-kick into the penalty area.
Brighton midfielder Billy Gilmour was then shown a red card in the 81st minute for a foul on Amadou Onana – but Dunk headed in from a corner to secure the 10 men a point.
Everton goalscorer Branthwaite told BBC Sport: "We put in a solid performance. We went 1-0 up and then they went down to 10 men. Then we sat back and invited pressure - them scoring at the end is frustrating.
"They are a good team, with 10 men they could keep the ball. We pressed all game, then they went down to 10 men and we stopped pressing – I don't know what happened."
