Dutch international hits three to sink Sir Alex Ferguson's side.
Dirk Kuyt scored a hat-trick to give Kenny Dalglish's side a thoroughly deserved victory over their deadly rivals who, in truth, never looked like threatening their hosts.
The defeat leaves United three points clear of second placed Arsenal having played a game more and Ferguson will certainly be disappointed that his side were unable to capitalise on the Gunners' draw with Sunderland on Saturday afternoon, as they delivered a performance hardly befitting of their supposed superiority over their oldest foes.
The first half belonged to Dalglish's men and in particular Kuyt, securing a brace within five minutes. In truth he was the beneficiary of the sublime and the ridiculous. His first coming from a fantastic piece of individual play from Luis Suarez, with the Uruguayan slaloming inside the area to put the ball on the Dutchman's foot to break the deadlock. The second was to come from a terrible defensive header from Nani, who knocked the ball into the path of Kuyt to head home his second and put Liverpool firmly in the driving seat.
The second half was equally disappointing for Sir Alex Ferguson's side, who were lacking in almost every department. A few flickers of a comeback were soon extinguished as Kuyt secured his hat-trick, latching on to a rebounded save from Van der Sar who had looked to parry away a limp Luis Suarez free-kick. Javier Hernandez provided late consolation for the visitors but it will have offered cold comfort for United who have now suffered consecutive Premier League defeats for the first time since March 2009.
The match began amid a typically ferocious atmosphere and it was met with an admirable vigour on the pitch, most notably from the hosts who had a fine chance to secure a dream start in the opening two minutes, only for Luis Suarez's touch to let him down as he entered the box latching on to Raul Meireles' fine through ball. It was an early signal of intent from the Uruguayan, who was matching up against an unfavoured central defensive partnership of Wes Brown and Chris Smalling.
It was an atmosphere intended to intimidate the league leaders and the opening exchanges indeed suggested that Ferguson's side were rattled, failing to sustain a period of possession in the opening ten minutes, stunted by the pressure imposed upon them by the hosts' midfield.
Liverpool's opening dominance failed to yield a chance to trouble Edwin Van der Sar but the hosts were comfortably the better side in the opening quarter of an hour. However, Dimitar Berbatov delivered an effort befitting of United's season and despite being second best, it was the visitors who broke the deadlock. Collecting the ball just outside the Liverpool area, the Bulgarian swiped a half volley with typical languidity only to see it bounce off the outside of the post. Reina was certainly beaten and it was a wake up call for the hosts.
The best effort of the match was soon followed by the best chance as Raul Meireles benefitted from a glorious cross-field ball from Suarez to knock into an advancing Dirk Kuyt, only for the Dutchman to just miss out from what was an admittedly heavy-footed ball from the former Porto man who has impressed so often this season.
It had been a superb, if a little ineffective opening quarter from Kenny Dalglish's side and the clash was slowly showing a reversal in fortunes for both sides with Fabio Aurelio forced off through injury to be replaced by Soritis Kyrgiakos. For United, Dimitar Berbatov was proving the most prevalent thorn in Liverpool's collective side. The Bulgarian, who has been overlooked in favour of Javier Hernandez in recent weeks, was proving himself a worthy outlet for Sir Alex Ferguson's team.
It was looking ever more likely that it would take a moment of true quality for either side to break the deadlock and on the 33rd minute, it was provided by Suarez. The Uruguayan, collecting the ball in the box, somehow broke free from his markers, turning on a six pence and sliding the ball through to a grateful Dirk Kuyt to give the hosts a deserved lead from a yard out. It paid testament to Liverpool's endeavour and Manchester United, who were vocal in their calls for offside, had no cause for complaint.
A second for the hosts came only five minutes later and it was a case of going from the sublime to ridiculous. The move once again began with Luis Suarez, who, from the right hand channel, delivered a harmless ball into the box only for Nani, one of United's performers so far this season, to head the ball back into the danger area and directly on to the head of Kuyt who nodded home with consummate ease. The task was looking increasingly perilous for Sir Alex Ferguson with half time approaching.
If United didn't think that it could get any worse, injury was to be added to insult on the stroke of half time as Nani, felled by an awful challenge by Jamie Carragher, was taken off on a stretcher. The Reds defender protested his innocence as he was shown a yellow card but in truth, he was lucky not to have been dismissed.
As was Rafael only a minute later as the Brazilian cut through his compatriot Lucas with a rash lunge. He also received a yellow as the half ended amidst a melee of nearly every player on the pitch. The scenes were indeed ugly but they held the promise of an enthralling second period.
It was clear that urgency was required for the visitors but the first chance of the second half fell to Liverpool as Suarez, who had been unplayable at times in the first , weaved his way through United's defenders once again and nearly chipped Meireles in for a third. Sir Alex Ferguson's side held on but they would be largely thankful for some brave goalkeeping from Edwin Van der Sar.
Things certainly weren't clicking for the league leaders.
United were certainly showing signs of improvement, most probably with the hairdryer treatment of Ferguson still ringing in there ears as Rooney, who has been a peripheral figure throughout, made space down the left and lashed a superb ball into Ryan Giggs only for the Welshman to smash the bouncing ball over the bar as the hour mark neared.
The swagger of the hosts, so evident in the first 45 minutes, had retreated somewhat and it was from this hesitancy that United so nearly clawed one back, with Martin Skrtel nervously hoofing the ball out for a corner. From that, the ball fell to Berbatov only a couple of yards out but the Bulgarian was unable to breach the excellent Meireles who chested the ball off the line from the striker's header.
For all of United's tentative improvements, a goal was not to come and it was Kuyt once again to all but settle the tie, latching on to a Van der Sar save from a poor Luis Suarez free-kick. It wasn't a hat-trick of great invention but it's significance to the fans was evident as they piled down to the front of the Kop to congratulate the Dutchman.
The atmosphere was nearing party territory at Anfield as the game entered its final 15 minutes and the noise became deafening on the introduction of record £35 million signing Andy Carroll, as the former Newcastle man came on to replace the superb Raul Meireles.
Ferguson made moves to find a way back into the tie, with Darren Fletcher and John O'Shea entering the fray but it was a case of too little too late and it was an alarming indictment of the league leaders' resources that they failed to offer any real threat from the bench.
It nearly got worse still for United as Luis Suarez, whose performance certainly deserved a goal, broke down the right-hand side at will but failed at the final hurdle, slicing his effort high and wide into a jubilant Kop.
Consolation was to come for United as Hernandez, who had been his usual energetic self since replacing Nani latched on to a late header. There was no time for celebration however, the game, was very much up for the visitors.
The voracity with which You'll Never Walk Alone was belted out paid testament to a what was a sublime Liverpool performance. United may still be top dogs in the Premier League on paper but after two consecutive defeats, Sir Alex Ferguson's charges are look ever more the wounded animal as the title race reaches it's most pivotal point.
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