Ruud van Nistelrooy showed just why United splashed out £18million with two goals in as many minutes to give Fulham a harsh lesson in Premiership football.
The Holland international added to his Charity Shield strike with a second-half double as the reigning champions recovered from the shock of falling behind to Jean Tigana's newly-promoted side.
They were not the most of spectacular strikes, but his striking instincts put him in the right place at the right time to spare United's blushes and leave a muted Old Trafford crowd largely satisfied.
All eyes in the stadium and on Sky Sports were on van Nistelrooy and fellow new boy Juan Sebastian Veron, but the £46million duo were upstaged early on by Fulham's Louis Saha.
The Frenchman had flopped in his first crack at the Premiership with Newcastle, but showed he now has the class to trouble the best defences in the land with a shock opener just four minutes in.
The workaholic Sean Davis lifted an exquisite ball over the United back line and after pulling it down neatly, Saha sent a delicate lob over Fabien Barthez to stun everyone.
Sir Alex Ferguson responded by dragging off Phil Neville for Andy Cole and pushing Paul Scholes - who had somehow hit the post from little more than two yards - back into midfield and was rewarded with an equaliser on 35 minutes.
But the goal, as good as it was, came with a huge slice of fortune. Quite why referee Peter Jones gave a free-kick for Davis' tackle on Ryan Giggs only he will know. But everyone knew what was coming next and David Beckham did not disappoint, curling the 25-yard kick in off the underside of the bar.
Yet Fulham came roaring back and could have regained the lead had Barthez not kept out a powerful header from Saha and blocked Barry Hayles with his legs, before they finally went back in front after only two minutes of the second half.
Their own new boy Steed Malbranque picked Saha's run out and as Jaap Stam closed in and Barthez advanced, he slid a sublime finish inside the far post for a 2-1 lead.
Few people score twice at Old Trafford, but Saha was soon shunted out of the limelight by van Nistelrooy's deadly double.
First the Dutchman scooped Andy Cole's overhead kick over Edwin van der Saar and inside the far post to make it 2-2 and within 120 seconds, a Dennis Irwin cross came off Hayles and fell perfectly for him to smash home what turned out to be the winner.
He was then taken off to a standing ovation, while Veron soon followed, subdued after his World Cup exploits in midweek and van Nistelrooy's replacement Luke Chadwick should have won a penalty after a rash challenge from Alain Goma.
But a greater defeat would have been a gross injustice on Fulham, who matched the champions most of the way - until van Nistelrooy stepped up.
MAN OF THE MATCH: Louis Saha (Fulham) - A controversial choice, but his two fine finishes and constant threat just overshadowed the excellent van Nistelrooy.
Man Utd: Barthez, Irwin, Stam, Silvestre, Gary Neville, Giggs, Phil Neville (Cole 35), Veron (Brown 80), Beckham, Scholes, van Nistelrooy (Chadwick 77).
Subs Not Used: Carroll, Solskjaer.
Fulham: Van der Sar, Melville, Harley, Goma, Finnan, Davis, Malbranque (Ouaddou 88), Goldbaek (Stolcers 79), Collins, Saha, Hayles (Betsy 84).
Subs Not Used: Taylor, Symons.
Booked: Goma.
Att: 67,534
Ref: P Jones (Loughborough)
Source Sky Sports