Manchester United 4 Liverpool 0
A Ruud van Nistelrooy penalty double and late strikes from Ryan Giggs and Ole Gunnar Solskjaer sent Manchester United marching to Madrid with their Premiership title dream still alive.
Fierce north-west rivals Liverpool couldn't haul themselves back from the fourth-minute dismissal of skipper Sami Hyypia for a foul on van Nistelrooy which gave the Dutchman his first spot-kick chance.
Van Nistelrooy then lashed home his 34th goal of the season - and his fifth in two games - when Igor Biscan blocked off Paul Scholes in the box in the second half.
Ryan Giggs slid in to convert a cross from substitute David Beckham 11 minutes from time and then with virtually the final kick, Solskjaer completed the job with a shot which went through Djimi Traore's legs and beat Liverpool goalkeeper Jerzy Dudek at his near post.
With a two-goal cushion, Beckham and John O'Shea were introduced for Neville and Silvestre, while Vladimir Smicer was brought on for Liverpool shortly afterwards in place of the hard-working Diouf.
Now the confidence started to ooze out of the home side. Solskjaer forced Dudek into a smart save at his near post, then Traore lunged at a low Giggs cross, almost turning it into his own net.
Another wild Gerrard lunge on Beckham gave Giggs a crossing chance, which he drifted aimlessly into Dudek's hands.
Fortunately for United, Beckham is not so profligate when he gets the ball in wide areas and though the wicked inswinging cross he delivered 11 minutes from time was just out of van Nistelrooy's reach, Giggs slid in to convert his first goal at Old Trafford in the Premiership for more than three years.
The referee finally lost patience with Gerrard for complaining at another foul awarded against his team and he became the third Liverpool man cautioned.
Gary Neville then volleyed marginally over from an acute angle, although if Liverpool thought their misery was complete, they were wrong, as Solskjaer drove home the fourth in the final minute, beating Dudek at his near post.