England International Striker Wayne Rooney make Crucial goal an injury-time winner to beat Manchester City in a pulsating 3-1 victory.
After Argentina Striker Carlos Tevez had threatened to take the semi-final into extra-time when he quite brilliantly turned home Craig Bellamy's cross 14 minutes from time, up popped Rooney, who nodded home Ryan Giggs' cross to secure a Carling Cup final meeting with Aston Villa on February 28.
In fact, Manchester United thought they were already there.
Controlling possession against a City side which sat too deep, they had carved out a decisive lead thanks to two precise finishes from Paul Scholes and Michael Carrick either side of the interval.
Only Carloz Tevez's refusal to bow at the feet of his old club kept the Blues going, but it was not enough. And though Wayne Rooney inexplicably failed to grab a third before Tevez struck, he is too much a part of United's fabric to merely accept defeat.
Manchester City were attempting to "change history'' in Mancini's words.
In pure domestic and European terms alone, United had made 21 cup final appearances and won 11 league titles since the Blues last reached Wembley in 1981.
Tevez was the clear focal point for City from the start. The South American flung himself at a Bellamy cross and Edwin van der Sar needed Jonny Evans' help to ensure there was no trouble after he had dropped what seemed to be a routine save.
Rio Ferdinand got away with a despairing lunge at Tevez that left the former United man on the deck. If referee Howard Webb had been feeling in a stricter mood, the gamble of playing Ferdinand this evening and leaving the consequences to be faced tomorrow when he goes before an FA disciplinary panel could have backfired disastrously.
As the teams trooped in for their half-time pep talk, the feeling persisted that the game was destined to explode.
The firecracker went off seven minutes after the restart and following a brief stoppage after Bellamy had been hit on the back of the head by a coin as he went to retrieve the ball for a City corner.
United quickly countered as City conceded possession. Rooney delivered a superb pass for Giggs, who would have had a clear sight of goal if City goalkeeper Shay Given had not been so quick to react and push him out wide.
The veteran Welshman did not panic and delivered the ball back into the City area and, after, Nani had run into a wall of defenders, Michael Carrick prodded the ball back for Scholes, who drove his shot into the bottom corner.
Manchester United had the scent of Wembley in their nostrils and when Nani flicked a superb pass through to Darren Fletcher inside the City box, the Scotland star had the awareness to lay a pass off to Carrick. The England midfielder does not score many, but he is an accurate striker of the ball and his shot was perfectly placed into the bottom corner with the aid of the post.
If Wayne Rooney had tapped home Patrice Evra's cross when he was completely unmarked three minutes later, the tie would have been over. Inexplicably, he put it wide.
It was virtually certain Rooney would be made to pay almost instantly. After playing a pass out to Bellamy, Carlos Tevez continued his run and somehow managed to squeeze the ball beyond Van der Sar from the most unlikely angle.
The Reds Devil could feel aggrieved but relief should have arrived 10 minutes from time when Vincent Kompany's block offered Michael Carrick a second chance. On this occasion though his snap shot flew wide. But Wayne Rooney still had one more trick up his sleeve.
