What promises to be the most difficult 18 days of Sir Alex Ferguson's career as Manchester United manager began with one of his most memorable results.
Over the next three weeks, United will play Real Madrid twice in the Champions League quarter-finals, and Newcastle, Arsenal and Blackburn in the Premiership.
But there could be no more satisfying start to such a daunting schedule than a 4-0 win over their bitterest rivals.
Liverpool were staring down the barrel of a gun after only four minutes.
Paul Scholes' clever pass with the outside of his boot 20 yards out found Ruud van Nistelrooy who glided past Liverpool sipper Sami Hyppia into the box before being brought down by the Finn.
Referee Mike Riley pointed to the penalty spot and then dismissed Hyypia as there was no other Liverpool player between van Nistelrooy and goalkeeper Jerzy Dudek.
The Dutchman stepped up to drive his right-foot spot kick beyond the despairing dive of Dudek and into the right corner of the net.
But the expected onslaught against 10-man Liverpool never materialised.
Igor Biscan replaced striker Milan Baros to leave Emile Heskey isolated up front.
It was United's turn to feel aggrieved on the quarter hour when Mikael Silvestre's 12 yard shot into the net was ruled out by Mr Riley for supposed infringement by Wes Brown and Rio Ferdinand on Dudek as he punched clear.
The barometer of grievance swung back to Liverpool in the 65th minute.
Scholes looked to have run into Biscan as he went for the ball in the Liverpool box, but Mr Riley awarded another penalty which was slotted home in identical fashion to his first by van Nistelrooy.
Liverpool's normally tight defence was now starting to loosen and United made it 3-0 in the 79th minute.
David Beckham's cross from the right eluded van Nistelrooy in the six yard box, but Ryan Giggs, coming in behind, scored with an acrobatic left-foot shot - his first Premiership goal at Old Trafford for almost two years.
As the seconds ticked away, Giggs found Ole Gunnar Solksjaer free 12 yards out on the left side of the Liverpool penalty area and his crisp low left-foot shot rolled between Dudek and his near post and into the back of the net.