Paul Scholes' last-gasp goal stunned Manchester City as Manchester United caused their neighbours more injury-time heartbreak at Eastlands, as they won 1-0.
After Michael Owen's winner in the sixth-minute of stoppage time at Old Trafford in September, there were just 17 seconds of the three additional minutes left this time around as Scholes rose unchallenged to head home Patrice Evra's left-wing cross from 10 yards.
It was an amazing finish to a game that seemed destined to end goalless.
For Scholes, who signed a one-year contract extension on Friday, it was his 149th Red Devils' goal and the perfect way to retain the outside title hopes United still cherish.
Yet again after a meeting with the team they are so desperate to usurp, City must lift themselves off the floor after suffering the most shattering of blows, still believing a Champions League place can be theirs.
After his appearance against Bayern Munich 10 days ago, it was hardly a surprise that Wayne Rooney should declare himself fit after just a single day's training.
But the prospective PFA player-of-the-year looked ill at ease, repeated rants at referee Martin Atkinson and a petulant kick at Nigel de Jong belied his mood.
Rooney appeared tentative, he declined to set up Ryan Giggs when he had the chance to do so, and there was no real conviction behind his only decent opportunity of the opening period, when Antonio Valencia forced the ball into the area.
Having beaten Kolo Toure with a deft piece of skill, the goal opened up for striker, who had scored 34 times before his unfortunate ankle injury.
He dragged the effort wide though, which only increased his frustration, his contribution eventually brought to an end 15 minutes from time when he was replaced by Dimitar Berbatov.
Rooney's attack on De Jong might have been revenge for a thunderous challenge from the Dutchman on Patrice Evra, which set the tone for an opening period high on energy but low on goalmouth incident.
A bulldog of a midfielder, De Jong gave United little time to settle on the ball, and though the visitors had plenty of possession, much of their passing was of a sideways variety.
Only Antonio Valencia looked as though he could cause the Blues significant problems.
Having escaped a penalty-box handball that went unseen by Atkinson and, apparently, the entire United team, returning full-back Wayne Bridge was undone by the Ecuador man just before the break.
Valencia squeezed a cross through to the near post where Giggs was alert enough to make contact, but lacked the power to beat Shay Given with a low flick.
For their part, City seemed to have more movement but invariably ran into a defensive brick wall.
Against his old club, Carlos Tevez curled an early free-kick towards the top corner only for Edwin van der Sar to make an excellent save.
It turned out to be the sum total of first-half efforts on goal from Roberto Mancini's men, a fizzing low cross from Craig Bellamy not much to enthuse about considering his team had scored 11 times in their last two outings.
The was no discernable improvement - either in the overall quality or Rooney's temper - in the opening minutes of the second-half.
It did Rooney no credit at all that when he was kicked by Vincent Kompany, he rolled around in apparent agony then jumped to his feet and ran off without a problem once the yellow card had been brandished.
The problem for United was that with their bulwark at less than full throttle and Valencia their only source of pace, they were reliant on guile alone to open City up.
City had more speed and a flowing move, started by Emmanuel Adebayor and inevitably involving Tevez, ended when Craig Bellamy crashed a shot into the side-netting.
Shortly afterwards, the Blues had a penalty appeal turned down.
Gareth Barry could be accused of making too much of minimal contact by Gary Neville. There was certainly contact though, and not with the ball on Neville's part.
The crowd were still digesting that incident when Giggs got on the end of a long ball beyond the City defence and would have been clean through if he had not been confronted immediately by Given, whose goal was threatened by Berbatov with a deft header shortly afterwards.
It then took the interventions of Nemanja Vidic and Darren Fletcher to ensure a goalmouth scramble caused by Van der Sar's ill-advised charge to meet a cross did not ended in disaster for the visitors.
This flurry of activity gave the impression of a game finally heading somewhere. It took Scholes to find the map.
Sir Alex Ferguson hailed Paul Scholes for keeping Manchester United's Premier League title hopes alive.
He told Sky Sports: ''It would have been very, very difficult if we had not
won. I think we deserved to win the match, no question, but I couldn't see a goal
''I decided to put Scholes a bit further forward and it paid off. He was man of the match today, he was wonderful, he's such a skilful player.''
Ferguson also paid tribute to the influence of Ryan Giggs and Gary Neville. He added: ''The experience in these games in definitely important and can be vital in helping other players as well as their own contribution.''
With Wayne Rooney back after an ankle injury, United carved out a number of chances but were unable to convert any of them until Scholes struck.
The England striker looked frustrated and was replaced in the second half by Dimitar Berbatov. That came shortly after he was left rolling on the floor following a challenge from Vincent Kompany, which saw the City player booked.
Rooney suddenly recovered, then raced away and Ferguson said: "I asked him why he got up. He said it was because he thought Kompany was getting sent off so he jumped up. Then the crowd booed. It's a cruel world."
Neville said United needed a positive result after the disappointment of their
Champions League exit. He said: ''We were hoping for something today as we had not had a great two weeks. Scholesy had passed them to death all day and gives us a little bit of
life. We just have to hope someone does us a favour.''
Scholes' performance in midfield had helped United dominate the match in a game
of few chances and he said: ''I think we were the team pressing to try to score and
fortunately we were lucky enough to win the game with not much time left. It's nice to win any game against City and away from home especially.''
City boss Roberto Mancini said he was ''angry and disappointed'', claiming: ''That's football, it's incredible, but for us it doesn't change anything, we have another four games. We are very disappointed to lose and I'm very angry but always positive. We had some chances and we didn't deserve to lose but that's football.
''We played a good game but it was difficult for us and United, and when
Scholes scored in the last few seconds it was unlucky. This doesn't change the situation for fourth place - the crucial match will be against Tottenham here.''