Kenny Miller gave Wolves the shock result of the Premiership season to dent Manchester United's title hopes.
Miller's measured second-half finish stunned the champions and revived Wolves' hopes of avoiding relegation.
Sir Alex Ferguson's side dominated possession, but Miller raced clear to score in the 66th minute.
United, who lost injured Rio Ferdinand as he starts an eight-month ban, were also fortunate when veteran former midfield man Paul Ince struck a post.
Wolves boss Dave Jones will hope he result can ignite a revival from a side many have already written off as doomed to relegation.
But for United it was a desperate result and gives fresh hope to the chasing title pack.
They were without Ryan Giggs with a back injury, but it did not stop Ferguson's side virtually dominating possession for the entire first half.
Ruud van Nistelrooy, predictably, was the major threat as Wolves were forced to mount a lengthy rearguard action.
He sent an overhead kick narrowly over the bar, and was then guilty of an uncharacteristic miss four minutes before the interval, heading over the bar from virtually on the goal-line.
And yet it was Wolves who came within inches of taking the lead in the 48th minute when former United star Ince struck the post with a measured right-foot drive from 25 yards.
United suffered a blow seconds later when Ferdinand, struggling with a knee injury after a 14th minute collision with Kenny Miller, was finally forced to limp out of the action, being replaced by Wes Brown.
For all United's supremacy, Wolves goalkeeper Michael Oakes had been well-protected until he was forced into a fine diving save from Paul Scholes' close-range effort.
Wolves had shown great resilience to hang on, and their efforts were rewarded when they took a dramatic lead after 66 minutes.
Ferdinand limped off injured
Miller picked up a ball from a loose United throw-in, evaded Brown with surprising ease, and slid a cool finish past Tim Howard.
United boss Ferguson was stung into action, replacing Phil Neville with Diego Forlan.
It was another United substitute David Bellion, on for Darren Fletcher, who almost provided the equaliser with 16 minutes left when he worked space inside the penalty area but was denied by Oakes.
But Wolves held on to spark scenes of mass celebration inside Molineux at the final whistle.
Wolverhampton: Oakes, Irwin, Craddock, Butler, Naylor, Newton,
Ince, Rae, Kennedy, Miller, Iversen (Ganea 80).
Subs not used: Cameron, Clyde, Kachloul, Ikeme.
Booked: Butler, Ganea.
Man Utd: Howard, O'Shea, Ferdinand (Brown 50), Silvestre,
Fortune, Fletcher (Bellion 65), Keane,
Phil Neville (Forlan 68), Ronaldo, Scholes, Van Nistelrooy.
Subs not used: Butt, Carroll.
Referee: A D'Urso (Essex).