If there is one Liverpool player who is a constant thorn in the side of Manchester United it is Danny Murphy.
The England midfield man, more than his higher profile international colleagues Michael Owen and Steven Gerrard, is United's bogey man.
His 63rd minute penalty gave Liverpool victory and, although United won this fixture 4-0 last season, goals by Murphy in the two previous campaigns gave the Merseysiders a back to back 1-0 Premiership wins at Old Trafford.
The only goal of a poor game came when Gerrard's surging run into the left side of the United box saw him upended by Gary Neville.
Referee Mike Riley pointed to the spot and Murphy coolly stepped up to hit his right-foot shot to United goalkeeper Tim Howard's left and into the top corner of the net beyond the American's despairing dive.
The result put Liverpool three points clear of Newcastle in that crucial last position for a place in next season's Champions League, although the Geordies have two games in hand.
While United are assured of at least third spot, this defeat makes it more likely that they will have the indignity of a qualifier to face before joining Europe's elite next season.
United could have few complains about the result.
Without top marksman Ruud van Nistelrooy through injury and Paul Scholes suspended, they lacked craft and those vital qualities needed to break down an obstinate Liverpool defence.
Louis Saha too often faced the bulk of Liverpool defensive heavyweights Sami Hyypia and Stephane Henchoz on his own with support in the box too slow to arrive.
It was only in the latter stages of the game when substitute Ole Gunnar Solskjaer replaced defender John O'Shea that United really threatened.
Although hardly a grandstand finale, Liverpool's defence was finally put under real pressure in the last 15 minutes.
Saha created a couple of half chances in the opening minutes of the game and United's only shot on target in an sterile first half in which the game threatened to suffocate among the bodies of a blanket midfield, came in the 17th minute.
Roy Keane pulled the ball back from the right by-line to Darren Fletcher on the edge of the penalty area.
His cross to the far post found Saha, whose shot from eight yards went straight at Liverpool goalkeeper Jerzy Dudek.
Liverpool had caught United sleeping four minutes earlier when John Arne Riise's long throw on the left found Owen free on the by-line.
But Owen proved too advanced for any of his team-mates and when he knocked the ball back across goal there was no player in sight.
United winger Cristiano Ronaldo opened first on the left and later on the right, causing Liverpool some problems.
The Portuguese teenager produced one acrobatic shot from a Fletcher cross, but his effort from 12 yards fizzed over the bar.
Soon after, Ronaldo's petulance earned him a booking when he threw the ball down in disgust after a throw-in decision went against him.
Another Ronaldo cross from the left forced a fine defensive clearance by Riise, while Ryan Giggs curled a 25-yard free-kick from the right edge of the Liverpool box narrowly wide of the far post.
Liverpool were creating little at the other end, although Hyypia's free header from a Murphy corner went tamely at Howard.
United missed a good opportunity to break the deadlock two minutes from half time.
Howard's long goal kick was headed on by Saha and Giggs raced on to the bell. The Welshman beat Hyypia on the left side of the penalty area, but hit his shot from 12 yards high over the bar.
Ronaldo's tremendous skill was apparent early in the second half when he beat three Liverpool players as he cut in from the right before hitting his final pass straight to a White shirt.
Liverpool boss Gerard Houllier brought on winger Vladimir Smicer for defender Steve Finnan in the 59th minute and the Anfield men began to open out from defence.
Owen was inches off capitalising on a poor backpass by Wes Brown seconds later - Howard's alertness saving the day for the Red Devils.
Liverpool scored soon after and United's Red Army of fans must have sensed the inevitable that came with a Murphy goal at Old Trafford.
Yet, United managed to raise their attacking game in the closing stages.
United's best chance of the match came in the 79th minute.
Fletcher found Saha on the right side of the Liverpool box and his cross picked out Giggs racing in free on the far post to hit a blistering shot from 12 yards which hit the near post and rebounded across the line on to the far post before being cleared.
Seconds later, Giggs returned producer for Saha when his cross from the left was headed narrowly wide by the Frenchman.
With five minutes to go, Giggs again set up Saha, whose shot from the edge of the penalty area was saved at full stretch by Dudek.
After the match, a delighted Liverpool manager Houllier said: "When you win at Old Trafford, it is always a great performance.
"You need legs, discipline, energy, teamwork and you need to work extra hard for each other.
"We had a bit of luck at the end of the game when Ryan Giggs' shot hit both posts.
"Murphy has not played many games, but he was tactically aware and astute and did very well.
"When you have Cristiano Ronaldo on one side and Ryan Giggs on the other you need to double mark.
"The battle for fourth place will go right to the end of the season. There will be twists and turns all the way until our last match which is against Newcastle.
"I am sorry for the fans that we dropped five points at home to Charlton and Fulham, but we made up a bit for that." United manager Sir Alex Ferguson said: "It was a strange game. We never built up any tempo to it and we had an over fussy referee.
"Players from both sides did not really get into it and it was stop-start, stop-start all the way.
"We had five chances through Saha (twice), Solskjaer (twice) and Giggs, but did not make their keeper work.
"We had no complaints about the penalty. We still had chances to win it, but it was not a good performance.
"Liverpool showed more composure for a spell in the second half and it was a good result for Gerard Houllier." Man of the Match: John Arne Riise - Proved a kingpin at the heart of the Liverpool defence and provided several crucial interventions to keep United at bay.
HASH(0x8b5b990)