No matter that Carragher had been withdrawn after 63 minutes, long before the explosive winning goal was scored by Dirk Kuyt.
Dutch of class: Dirk Kuyt blasted Liverpool into the fifth round of the FA Cup
MATCH FACTS
Liverpool: Reina,Skrtel,Carragher (Kuyt 63),Agger,Kelly, Henderson,Gerrard (Bellamy 72),Jose Enrique, Downing, Carroll, Maxi (Adam 63) Subs Not Used: Doni ,Johnson, Coates, Shelvey.
Goals: Agger 21,Kuyt 88.
Man Utd: De Gea,Rafael Da Silva, Smalling, Evans, Evra, Scholes (Hernandez 76), Carrick, Giggs (Berbatov 90),Valencia, Welbeck, Park. Subs not used: Lindegaard, Ferdinand, Fabio Da Silva, Michael Keane, Pogba.
Goals: Park 39.
Booked: Rafael Da Silva.
Att: 43,952
Ref: Mark Halsey (Lancashire).
Goals: Agger 21,Kuyt 88.
Man Utd: De Gea,Rafael Da Silva, Smalling, Evans, Evra, Scholes (Hernandez 76), Carrick, Giggs (Berbatov 90),Valencia, Welbeck, Park. Subs not used: Lindegaard, Ferdinand, Fabio Da Silva, Michael Keane, Pogba.
Goals: Park 39.
Booked: Rafael Da Silva.
Att: 43,952
Ref: Mark Halsey (Lancashire).
No matter that Carragher had been withdrawn after 63 minutes, long before the explosive winning goal was scored by Dirk Kuyt.
The veteran defender is the closest thing to the personification of Liverpool Football Club and yesterday was one of those days when that club could believe in itself again.
They have a Wembley date in the Carling Cup final to look forward to and now passage to the fifth round of the FA Cup. They may even start eyeing a double on Merseyside, and all this just a week after the abject capitulation at Bolton.
Yesterday, though, by the time Carragher had reached the tunnel, the fans' chants had changed from Anfield's traditional anthem to their playful song celebrating Luis Suarez.
That gave the impression that, for some, this fixture was seen as some kind of rematch of the FA disciplinary hearing which found Suarez guilty of racially abusing Patrice Evra at this ground in October and banned him for eight games, including this one.
Why else chant the name of a player who has made no contribution to the match?
It was, of course, inevitable that such a highly contentious issue would stalk this match.
First blood: Daniel Agger powered home from a corner to hand Liverpool the lead
First blood: Daniel Agger powered home from a corner to hand Liverpool the lead
It was, of course, inevitable that such a highly contentious issue would stalk this match.
Kenny Dalglish was right to point out that both clubs had done much to limit the vitriol in the run-up to the game; but he was wrong to suggest: 'Both sets of supporters were magnificent.'
It was not as bad as some feared but there were chants from the United end of 'racist b******' and 'self-pity city', while Evra, the injured party in all this, was booed throughout and traduced as a 'lying b******'.
Dalglish was incredulous when it was suggested he or anyone might be disappointed by that. 'Have you played football?' he asked. 'I've been booed.'
It is impossible to say whether the abuse affected Evra's game but he was badly out of position when, from Pepe Reina's goal-kick with two minutes remaining, Andy Carroll flicked the ball on for Kuyt, who was inside Evra and had a clear run at goal, to finish.
Goal time: David de Gea was questionably positioned for the opener
David de Gea, who had a miserable afternoon on his return to the United team, might have saved his team but was wrong-footed and beaten at the near post.
'I don't know how we lost it,' said Sir Alex Ferguson, who described defeat as a 'devastating blow'.
For Dalglish it was 'a fantastic effort' after the draining semi-final on Wednesday. And unlike last weekend, when he attacked his own side's commitment, yesterday he said: 'I can't speak highly enough of them.'
In truth, the result was an aberration in some respects, as for long periods United had controlled the game with Michael Carrick, Paul Scholes and Ryan Giggs unfazed in midfield.
Sideshow: Manchester United's Patrice Evra had to put up with jeers from the crowd
That was just prior to Liverpool's opening goal on 20 minutes. Steven Gerrard's driven corner required a strong presence but De Gea approached his task tentatively and collided with the immovable object that is Carroll.
No prizes for guessing who came off best. While De Gea was politely attempting to reach the ball, Daniel Agger rose to head firmly home.
Anfield roared but Liverpool retreated, dropping so deep that they were encamped on the edge of the penalty box, a tactic that might have been commendable had they been able to maintain concentration until half-time at least.
Striker: Park Ji-sung hauled Manchester United level before the break
The Korean met it first time, driving into the near corner so quickly that Reina barely had time to react.
United continued the second half as they had finished the first - on top - but for all their possession there was precious little end product.
Carragher, playing in holding midfield, was effective in that respect but when he came off and Kuyt and, later, Craig Bellamy came on, Liverpool looked more dangerous than ever.
Watching on: Luis Suarez, serving his suspension for racially abusing Evra, was in the stands
He might have added a third right on 90 minutes when his header at the far post crashed against the upright and Kuyt steered the ball wide from the rebound.
There will be no eulogies for Carroll yet, however.
Dalglish said he would receive a simple: 'Well done.'
Atmosphere: The Liverpool fans created a thunderous level of noise throughout the match
Yesterday, though, they got some immediate returns.