"I like the Carling Cup," began Sir Alex Ferguson's programme notes. Appreciation for the ugly duckling of competitions came late in life but the silverware that his new-found fondness has yielded is now accompanied by a sense of shame. United boast a hat-trick of wins in the past seven seasons, but they have suffered three embarrassing exits to Championship sides; Southend, Coventry and now Crystal Palace. Celebrations have mingled with humiliations.
In a tournament that doubles up as a laboratory for Ferguson, this particular experiment blew up in his face. The Manchester United manager often flirts with failure when trusting his reserves. This time the relationship was consummated.
"My apologies are to our fans because that was not a Manchester United performance," said the 69 year old. Some of the personnel involved should not be Manchester United players and Glenn Murray, once of Wilmington Hammerheads, struck the nail in the coffin of their challenge, leaving Palace jubilant and Ferguson facing the unwanted scenario of either Liverpool or Manchester City lifting the most winnable trophy.
Ferguson's first honour came against Palace; 22 years and 37 prizes later, revenge was belatedly exacted as the Eagles landed a place in the last four. The Scottish manager serenaded joyously was Dougie Freedman, in between the odes to his deserving charges.
"Glad all over," they sang; they were great all over the pitch. From Murray and Darren Ambrose, the superb substitutes, to Freedman's first picks, from the stalwarts at the back, Paddy McCarthy and Anthony Gardner, to the free-running, fast-improving Wilfried Zaha, part of a precocious right-sided pairing with Nathaniel Clyne.
While some of the United players are marginal figures, consider Stuart O'Keefe: the Palace midfielder has not been granted a single minute of Championship action this season but battled bravely for 120 at Old Trafford. "A fantastic, mammoth effort from their players," said Ferguson. "Every one of them worked their socks off."
Then consider their United opponents; with a starting 11 costing over £65 million - Dimitar Berbatov accounting for almost half of that - the home side produced a performance that was so flat and so insipid that the thought Murray's winner was offside could only be proffered as an excuse, not an explanation.
Naming and shaming would be a lengthy process, but the initial inquest should begin with Jonny Evans, the stand-in captain leading by the wrong sort of example by being partially culpable for both goals. Berbatov, ineffective for the opening 45, departed at half-time; injured, though Ferguson could have been forgiven for substituting several. While he came close with an overhead kick, the mediocre Mame Biram Diouf's evening was epitomised by his inability to take a legitimate throw-in. This was a night when United struggled with the basics.
In comparison, Palace scored the spectacular. Ambrose's unstoppable 35-yard shot flew past Ben Amos to break the deadlock. It was all the more surprising as it was their first goal in 523 minutes, since it was Easter (Jermaine Easter, to be precise) in October. Ambrose then provided the winner, Murray heading in his free kick, before illustrating again with a 35-yard effort - well-saved by Amos - that long-range specials are his party-piece, a talent that made him a teenage prodigy a decade ago.
As it was, the Manchester public - or, judging by the empty seats, some of them - came to see United's future and, until the replacements Ravel Morrison and Paul Pogba added invention and urgency, witnessed only Palace's promise instead, that of Zaha in particular.
Reputations can be enhanced or endangered on such occasions. Six months ago, Fabio da Silva was a Champions League finalist. Here, tormented by Zaha, booked for illegally exacting revenge and then limping off, the Brazilian failed his trial by teenager.
Yet youth was briefly United's salvation. Three minutes after Ambrose scored, Federico Macheda won and converted a penalty. Having acquired the momentum, United casually let it slip, playing with a damning lack of purpose.
In contast, there was a focus to Palace. "I thought every single player stuck to our gameplan," said Freedman. "They should be proud of themselves. I thought they stuck together. I felt in the last 15-20 minutes of extra time that desire shone through in the end."
It may be all the greater as such occasions do not come along often in a career and Murray, formerly of Stockport, Carlisle, Rochdale and Brighton, seized his chance to send Palace into a semi-final double-header with Cardiff. A Championship side will be in the Wembley final, a draw that rendered United's failings all the more galling.
"A very disappointing night," concluded Ferguson. The expression on his face suggested it was worth that that. This was a day when he loathed the Carling Cup.
MAN OF THE MATCH: Darren Ambrose. In a side of Palace heroes, Ambrose gets this vote for his incision. His goal was one of the greats by a visitor at Old Trafford. "A wonderful strike by Darren," said Freedman. "He's been doing it through his career."
MANCHESTER UNITED VERDICT: All in all, it was probably their worst day since Leeds won at Old Trafford in the FA Cup in January 2010. As Ferguson accepted, they did not even test Palace goalkeeper Price in the first half and, when Antonio Valencia then broke clear, he missed the target. Only Morrison, who twice came close, actually looked like scoring in open play and, of the starting 11, perhaps only Chris Smalling turned in a decent display. Macheda was strangely deployed on the left wing for the first half, before faring better as a striker but the majority dented their chances of featuring in their near future, and not merely because some played 120 minutes three days before the trip to Aston Villa.
CRYSTAL PALACE VERDICT: "There was no tactical genius," said a modest Freedman, but his players were evidently as organised as they were motivated. They showed a fine blend of individual ability and great teamwork and thoroughly deserved the result. The downside was that a team who face a game on Friday night lost the left-sided pair of Sean Scannell and Dean Moxey to injuries. Hopefully both will be fit to face Cardiff in the semi-finals; it would be harsh if any of this side were to miss out.