Cristiano Ronaldo scored a decisive double to settle a thrill-a-minute Premiership clash which saw Fulham boss Chris Coleman sent off. Ronaldo drove home a stunning first-half free-kick, then wrapped up victory four minutes from time with an equally clinical close range finish.
The winger's efforts punctuated an amazing contest which Coleman will always look back on with disgust at the match officials' failure to spot Ruud van Nistelrooy clearly standing a yard offside in the build-up to United's third, which Louis Saha prodded home.
The goal gave Sir Alex Ferguson's men some breathing space, which was just as well given Fulham pressed hard at times in the second period, although United were able to hold out for a win which reduces Chelsea's lead to 12 points.
The action began within two minutes as Park Ji-sung fed Van Nistelrooy, whose smart shot on the turn was beaten away by Antti Niemi, the start of a duel which was to become a feature of the contest.
Niemi then superbly kept out a Wes Brown volley, raising the suspicion the Finn was going to produce one of the performances of his life to deny the hosts.
Yet, it wasn't long afterwards Niemi's luck ran out as Park turned onto Neville's low cross, then chipped an effort towards goal which took a massive deflection off Carlos Bocanegra and flew into the corner.
It was Park's first Premiership goal and brought the South Korean press corps to their feet in delight. And soon the United fans were replicating their Asian visitors' high fives as Ronaldo blasted home his free-kick.
For all his faults, Ronaldo is a huge talent and there are not many players around who could have swerved the ball left and right, which left Niemi stranded yet again as the winger's 30-yarder flashed into the roof of the Fulham net.
Within 13 minutes, it seemed United had wrapped up the victory, a notable achievement given Wayne Rooney had been left on the bench. Yet it proved only to be the start of a rollercoaster ride.
With Nemanja Vidic, the most expensive component of his £12 million defensive outlay during the transfer window, alongside Rooney in the dugout, Ferguson must have been hoping for a more solid effort from his rearguard, whose lack of inches was twice exposed.
Brian McBride profited by leaping over Gary Neville on the first occasion and Heidar Helguson beat Patrice Evra with similar ease at the other post after Wayne Bridge had embarked on a blistering left wing raid.
In between those two efforts came the moment which got Coleman so steamed up - and with some justification.
When Saha prodded home United's third, pouncing on the loose ball when Niemi again repelled Van Nistelrooy, Coleman immediately raced to the TV monitor sensing an offside had been missed in the build-up.
How right the Fulham boss was too as Van Nistelrooy was clearly a yard off when he took Saha's pass before firing the shot which resulted in the Frenchman's ninth goal in 12 games.
Coleman instantly shot out of the dug-out and offered the assistant responsible a forthright opinion, which referee Martin Atkinson deemed worthy of being dispatched to the stand.
The Welshman's anger had clearly not subsided at the interval judging by the forceful manner in which his side began the second half.
Steed Malbranque almost capitalised on United's defensive vulnerability with a shot Edwin van der Sar needed to claw away after it had taken a deflection off Mikael Silvestre.
By that stage, Silvestre was partnering Vidic at centre-half after the Serbian had replaced Neville in a double change that also brought Rooney's introduction.
However, for once, Rooney was nothing more than a bit part player and it was Ronaldo who finished Fulham off with a clinical low, angled drive after Niemi had once again denied Van Nistelrooy.