Sensational Leeds produced fantasy Champions League football to clinch a place in the quarter-finals as boss David O'Leary's side threw the form book out of the window.

A devastating first-half performance of cut-and-thrust left Anderlecht's previously proud record at the Stade Constant Vanden Stock in shreds, and forced coach Aime Anthuenis to eat a large slice of humble pie.

Strikers Alan Smith and Mark Viduka ended their recent goal droughts in destructive style against the Belgian champions, who had won 21 successive home matches, as well as their last nine in Europe.

Such an astonishing run had included the notable scalps of PSV Eindhoven, Dynamo Kiev, Lazio and Manchester United, but Leeds made a mockery of such form at a ground which had proved a virtually impenetrable fortress.

Anthuenis had claimed after his team's 2-1 defeat at Elland Road last Tuesday that Leeds were not a good side, but Smith, Viduka and the rest rammed those words back down the throat of the 57-year-old.

It was another display which will undoubtedly confound those critics who have consistently written off Leeds since the draw for the first group stage in which they were paired with Barcelona and AC Milan.

The Spanish giants were sent spinning into the UEFA Cup at Leeds' expense, and then when O'Leary's side were rewarded for their remarkable endeavours with matches against Lazio and Real Madrid for the second group stage, the presumption was their luck would run out.

But more by design than by luck, Leeds have defied the odds in the face of domestic inconsistencies which have left O'Leary frustrated, not least because of the problems which have blighted Leeds' season both on and off the pitch.

A wretched injury crisis wrecked the first half of the campaign, with the last few weeks - and those ahead - currently dominated by the trial involving Lee Bowyer and Jonathan Woodgate at Hull Crown Court.

Bowyer, despite being one of the principal architects of Leeds' Euro adventure, the midfielder having scored five goals in the Champions League this season, was barely missed as he was also suspended.

That is testimony to the character and resilience of O'Leary's team, but during an unforgettable first half they added the flair which has long been missing from their armour.

As the smoke cleared from a score of red flares which greeted the teams, it was Smith who emerged from the mist to end an 11-week goal drought.

Smith had not scored since netting the winner against Lazio in Rome on December 5, but took his tally to 10 for the season - and four in Europe - by sweeping home Mark Viduka's 14th-minute cross.

The 20-year-old has been forced into playing mainly as a substitute since the high-profile arrival of Robbie Keane, but with the Republic of Ireland international star ineligible for Champions League football, Smith has stepped back into the breach.

Any disappointment from O'Leary at Danny Mills' 27th-minute booking - ruling out the right-back for the game in Madrid in a fortnight - was short-lived as Leeds tore Anderlecht apart, taking a 2-0 lead six minutes later.

Leeds spread the ball from right to left, with Olivier Dacourt feeding Dominic Matteo and allowing the winger to deliver a whipped-in cross to the far post where Viduka planted a looping header over the hapless Zvonko Milojevic.

For the Australia international it ended a run of nine matches without a goal, and from that moment the confidence in the United camp soared to such an extent they sublimely carved open Anderlecht again in the 38th minute.

French star Dacourt first supplied Viduka, with a cheeky backheel sending David Batty through and that was all the invitation needed for the midfielder to in turn put Smith in the clear.

As Smith ran on, the young striker stunningly chipped his second of the game over the advancing Milojevic, sparking jubilant scenes on the United bench and among the fans.

Anderlecht were effectively dead-and-buried, although they briefly threatened a comeback during a 10-minute purple patch during the second half in which Jan Koller beat Nigel Martyn's punch to head home what proved a mere consolation.

Either side of that Martyn produced superb saves to deny Bart Koor and Koller, before the game was finally killed off nine minutes from time when Ian Harte stroked home his fourth goal in eight matches from the penalty spot after Viduka had been brought down by Glen de Boeck.

All that remained after Norwegian referee Rune Pedersen's final whistle on a night to remember for Leeds was an agonising wait from Rome for the score from the Olympic Stadium.

At least three minutes elapsed before a 2-2 draw was confirmed, ensuring Leeds' qualification as the first English team into the last eight ahead of Manchester United and Arsenal - and at their first attempt.

Teams

Anderlecht: Milojevic, Ilic (Dindane 39), De Boeck, Crasson, Vanderhaeghe, Goor, Dheedene, Baseggio, Stoica, Radzinski, Koller.

Subs Not Used: Carlier, Van Diemen, Hasi, Pirard, Youla, Traore.

Booked: Baseggio.

Goals: Koller 76.

Leeds: Martyn, Harte, Radebe, Ferdinand, Mills, Matteo, Batty, Dacourt, Bakke, Smith, Viduka (Kewell 83).

Subs Not Used: Robinson, Wilcox, Burns, Maybury.

Booked: Mills, Harte.

Goals: Smith 13, Viduka 35, Smith 38, Harte 81 pen.

Att: 28,000

Ref: Rune Pederson (Norway).