If Dwight Yorke continues paying off chunks of his £12.5 million transfer fee at this rate, Manchester United will not only be in profit by the end of the season, they may also have won the treble.

The lethal Caribbean striker repeated his goal-scoring feat against Inter Milan to strike twice against Chelsea in their FA Cup quarter-final replay at Stamford Bridge, the second being an exquisite lob from 25 yards out.

The facts spoke for themselves - it was Yorke's 26th goal of the season and United's 100th in all competitions as they set up a Villa Park semi-final against Double holders Arsenal and inflicted Chelsea's first home defeat of the season.

Chelsea may have dominated large portions of the game but they were undone not only by slack early defending for Yorke's first after just three minutes, a lack of width and poor finishing but by the unparalleled Peter Schmeichel.

United's back four, with Jaap Stam back at the heart alongside Henning Berg, were immense and for a side often criticised for not matching their attacking flair with defensive resilience this marked their seventh clean sheet in 10 games.

Yet again though the headlines were stolen by Yorke. Both times he was set up by Andy Cole and both times he finished with aplomb to fully justify Alex Ferguson's single-minded determination to sign him last summer.

The class of United's victory at least managed to overshadow an unseemly moment when missiles were thrown at the United players as they marked their opening goal with a `baby' celebration - a la Bebeto - in honour of new-born Brooklyn Beckham.

There was also the worrying sight of Beckham senior having responded to foul abuse from the Chelsea fans by mouthing his own expletive back at them.

However, if there were any doubts that United are taking the FA Cup seriously, they were firmly dismissed not only by the ecstatic celebrations to mark Yorke's second goal but also by Alex Ferguson's line-up.

Back came Yorke and Cole after being rested at Old Trafford in last Sunday's goal-less draw, while Ryan Giggs and Stam also returned in a first-choice team.

Chelsea were boosted by Frank Leboeuf, Celestine Babayaro and Dennis Wise being back from suspension but had only beaten United in the FA Cup once before in eight attempts - way back in 1950.

The home side were also without full-back Albert Ferrer and it was his replacement, Bernard Lambourde, who gave the free-kick which led to United's early goal.

Beckham's cross was only headed into the air by Leboeuf and as the entire Chelsea defence remained rooted to the spot, Cole headed on to Yorke who was left unmarked to turn and volley past Ed De Goey from close range.

Two minutes later, Leboeuf again misjudged a cross, this time from Denis Irwin, and only Cole's control let him down.

From then on, Leboeuf and Marcel Desailly were impregnable at the back and Chelsea dominated possession only to find Schmeichel in fine form.

The Dane saved two shots from Jody Morris and then stormed off his line to brilliantly block an effort from Gianfranco Zola as the Italian sped onto Roberto Di Matteo's through ball.

Desailly headed inches wide but Chelsea patently lacked width and were forced to try to break United down through the congested centre of the pitch, leading to a string of wayward long-range efforts.

Chesea had to replace Leboeuf with Andy Myers at the break but still they came forward and Lambourde placed a header narrowly wide.

To add insult to injury, Wise met Babayaro's deep cross at the far post to side-foot goal-wards only to be denied by team-mate Tore Andre Flo, whose prostrate body deflected the ball out for a goal-kick.

But however penned back United had seemed, they took their second real chance of the game when Cole won a 50-50 tackle with Desailly and the ball fell to Yorke.

A full 25 yards out from goal, the striker spotted De Goey advancing off his line and produced an exquisite lob to leave the tall Dutchman grasping at thin air as he furiously back-pedalled.

Referee Paul Durkin, who this time escaped controversy after sending off Roberto Di Matteo and Paul Scholes at the weekend and failing to dismiss Robbie Fowler or Graeme Le Saux on his last visit to the ground, pointed to the centre-circle as United celebrated.

Chelsea did attempt to come back from the dead but Schmeichel did enough to put off Morris, Di Matteo drove narrowly wide and then substitute Mikael Forssell froze at the vital moment to fluff his chance from close range.

Teenager Forssell was joined on the pitch by Bjarne Goldbaek but United responded by introducing Phil Neville for Cole to man-mark Zola and Chelsea were unable to mount a recovery.

Schmeichel did manage to thwart them yet again to save Graeme Le Saux's late effort but it was Beckham who came closest to claiming a late goal with a curling free-kick which De Goey acrobatically pushed over.

"They are now going to play Arsenal which is good for us because obviously we hope they are going to use a lot of energy in that match," said Gianluca Vialli, attempting to take a positive from defeat.

"We had a lot of chances, but of course you have to score if you want to win. They did, and we didn't. That's why they went through."

Ferguson hailed Yorke for another marvellous contribution, saying: "26 goals and a lot of important goals. His temperament is excellent."

As for referee Paul Durkin, whom Ferguson criticised after Sunday's 0-0 draw at Old Trafford, Ferguson said: "The referee was outstanding. He is the best in the country and I think he showed it tonight."

Chelsea: De Goey, Lambourde, Desailly, Leboeuf (Myers 46), Le Saux, Wise, Morris (Goldbaek 71), Di Matteo, Babayaro, Flo (Forssell 71), Zola. Subs not used: Hitchcock, Newton. Booked: Desailly.

Man Utd: Schmeichel, G Neville, Stam, Berg, Irwin, Beckham, Keane, Scholes, Giggs (Blomqvist 75), Cole (P Neville 71), Yorke (Solskjaer 84). Subs not used: Van Der Gouw, Brown. Booked: Yorke. Goals: Yorke 4, 59.

Referee: P Durkin (Portland).