Sunderland dealt Manchester United's title hopes a crushing blow but the Black Cats' best result of the season could not stop them going down.
Sunderland's defence kept striker Wayne Rooney at bay
Needing a win to hold off relegation, Sunderland wasted first-half chances through Liam Lawrence and Jon Stead.
United improved after the break, but Kelvin Davis was in inspired form.
The Sunderland keeper made magnificent saves from Cristiano Ronaldo and Ruud van Nistelrooy to leave the hosts six points adrift of leaders Chelsea.
That gap will be nine points if the Blues win their game in hand against Bolton on Saturday, and with only four games remaining, that will surely end United's slim title hopes.
But they cannot claim to have been unlucky against a spirited Sunderland.
All but relegated before the kick-off, the visitors appeared to thrive on the pressure-free situation and were never afraid to go on the attack.
Lawrence had the best chance of the opening 20 minutes but shot straight at Edwin van der Sar.
As United toiled, the away fans even enjoyed the luxury of cheering every pass as the Black Cats kept possession in midfield.
But as the first half drew to a close, United began to show their class, even if they were guilty at times of over-elaboration.
Ji-Sung Park turned and ran straight at Sunderland's defence only to poke his shot narrowly wide.
Moments later, Rooney's deflected shot beat Davis but dropped on to the roof of the net as Sunderland breathed a sigh of relief.
However, a mistake by Ronaldo almost allowed Sunderland to snatch an unlikely half-time lead.
The winger was robbed in midfield and Justin Hoyte beat Van der Sar with his cross but Stead could not steer it home from a tight angle.
Sir Alex Ferguson might have been expected to dish out one of his famous 'hair-dryer' team talks at half-time but if he did, it did not have the required effect.
It took until the hour mark for the first clear-cut chance when Van Nistelrooy somehow failed to connect with Gary Neville's cross.
Davis was then on hand to beat out Ronaldo's shot before Hoyte almost stunned United with a surging run and left-foot shot.
But Davis was quickly back in the thick of the action, the keeper somehow getting down to his left to keep out Van Nistelrooy's snapshot.
Not surprisingly, United attacked with increasing desperation as the minutes ticked down, with Van der Sar coming to the halfway line to punt the ball forward, but Sunderland deservedly held on.
Manchester United boss Sir Alex Ferguson:
"With young players, you don't get the consistency.
"Tonight when we expected the most, Wayne Rooney and Cristiano Ronaldo had perhaps their worst game of the season.
"We need a miracle now obviously, but Chelsea still have three difficult away games and we have to go to Stamford Bridge and win. We can't give up."
Sunderland caretaker boss Kevin Ball:
"The way they played was magnificent, we didn't come to make up the numbers, we came to have a go.
"Every player was superb and there were opportunities for us to have won.
"We have to build on that, we've got five massive games and we need to build for the future. The main thing now is to prepare right for Monday against Newcastle."
Man Utd: Van der Sar, Neville, Ferdinand, Brown, Evra (Silvestre 67), Ronaldo, O'Shea (Solskjaer 67), Giggs, Park, Rooney, van Nistelrooy.
Subs Not Used: Howard, Heinze, Fortune.
Sunderland: Davis, Hoyte, Danny Collins, Breen (Caldwell 63), McCartney, Lawrence, Leadbitter (Miller 74), Whitehead, Daryl Murphy, Stead (Le Tallec 80), Brown.
Subs Not Used: Joe Murphy, Kyle.
Ref: R Styles (Hampshire).