Sharpen the guillotine and prepare to let those heads roll.

Sir Alex Ferguson should carry out Roy Keane's threat to make some Manchester United players a few inches shorter after they were dumped out of the Champions League by Bayern Munich.

Despite wake-up call after wake-up call, United could not pull out a performance when they needed it most.

Despite United's repeated Premier League triumphs, the true measuring stick of their season is the Champions League and for them, defeat in the last eight amounts to failure.

Indeed, United may have confirmed their ascendancy over Leeds in the Premiership this season, but David O'Leary's side have had the last laugh in Europe.

Bayern had lost just three of their previous 73 home matches in the European Cup, while they had conceded only one Champions League goal in the Olympic Stadium this season.

Not exactly the most encouraging set of statistics and the mountain United had to climb without the suspended David Beckham became even taller when Bayern scored with their first attack in the fifth minute.

Michael Tarnat received a diagonal pass in acres of space on the left and played the ball across to the back post where Giovane Elber scored left-footed from only two yards out.

That was just the kind of start United did not want and three minutes later it could have been even worse when Carsten Jancker broke through and crashed a drive off the underside of Fabien Barthez's bar.

United were a shambles and Wes Brown almost gift-wrapped a second goal for the Bundesliga champions when his weak back header was too short and Jancker nipped in only for Barthez to be on hand to superbly block the Bayern striker's goalbound effort.

Bayern had an injury scare in the 19th minute when Cole, looking to apply the finishing touch to a Mikael Silvestre cross from the left, accidentally caught Kahn with his knee.

The giant keeper laid motionless for several minutes - needing the kiss of life - and looked extremely groggy when he eventually struggled to his feet but, after receiving treatment, he opted to play on.

Bayern however wrapped United in a few more padlocked chains when they scored a second goal on 39 minutes.

Jens Jeremies beat Mikael Silvestre on the right before crossing to Elber who laid the ball along the line to the unmarked Scholl, who scored right-footed.

United were determined to go down fighting and Oliver Kahn saved a Cole shot before they gave themselves renewed hope four minutes after half-time.

Scholes played a delightful through ball to Giggs and the Welshman lifted the ball over the advancing Kahn into the Bayern net.

It was do-or-die time for United and as the match entered the last 30 minutes, they pushed Brown on to the right wing and played with three at the back.

Five minutes later Ferguson brought on Teddy Sheringham for Yorke and oh how United needed him to repeat his goalscoring heroics from Barcelona.

United kept up the pressure and Cole appealed in vain for a penalty after he went down under a challenge from Samuel Kuffour.

United desperately tried to increase the pressure on Bayern and Kahn tipped away a drive from Scholes. Brown was having a night to forget and Scholl turned him before shooting just past the post.

As the match entered stoppage time, Barthez left his goal to play as an extra outfield player just as Peter Schmeichel had done in Barcelona.

But this time there was to be no sensational comeback and Bayern had exacted their revenge.