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.

True, they dominated most of the second half, but by then the damage had been well and truly done.

Bayern deserved to win over the two legs and United suffered a bitterly disappointing end to their disappointing European campaign.

The joy at winning the Premiership title on Saturday has been replaced by despair at exiting the Champions League at the quarter-final stage for the second successive season.

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.

Ferguson admitted so before the game when he said it would be "a very flat year" if United lost to Bayern.

His mood as he contemplates a premature end to United's season will not be helped by the fact that those upstarts from across the Pennines are now England's sole representatives in the competition.

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.

United had faced a challenge as daunting as the one they had overcome in the Stadio delle Alpi against Juventus two years ago.

However the critical difference this time was that United are performing nowhere near the levels of 1999.

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 on the right and crashed a drive off the underside of Fabien Barthez's bar.

United's infamous travel sickness had taken hold once again and Bayern nearly capitalised on their malaise again when Elber's overhead kick rebounded off Jaap Stam.

United were a shambles and Wes Brown almost gift-wrapped a second goal for the Bundesliga champions.

Brown's weak back header was too short and Jancker nipped in only for Barthez to block the Bayern striker's effort.

United finally shook themselves into action and a Stam shot was deflected for a corner.

This heralded a spell of United pressure, which almost brought them a goal.

Nicky Butt flicked on Ryan Giggs' corner and Andy Cole's glancing header was cleared off the line by Mehmet Scholl.

Scholes then volleyed wide from a good position on the right to suggest that United might yet complete their greatest act of escapology yet.

However Bayern 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.

Giggs was denied a second goal when Kahn touched his piledriver away for a corner.

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. With time running out, United threw on the scourge of Bayern, Ole Gunnar Solskjaer and the home fans greeted his introduction with jeers.

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 the revenge they so desperately wanted.

Bayern Munich: Kahn, Kuffour, Andersson, Linke, Sagnol, Tarnat, Jeremies, Effenberg, Scholl (Sergio 88), Jancker (Zickler 35), Elber (Santa Cruz 64).

Subs Not Used: Dreher, Weisinger, Hargreaves, Kling.

Goals: Elber 5, Scholl 40.

Man Utd: Barthez, Gary Neville, Brown (Chadwick 85), Stam, Silvestre, Scholes, Keane, Butt (Solskjaer 78), Giggs, Yorke (Sheringham 66), Cole.

Subs Not Used: Van Der Gouw, Johnsen, Phil Neville, Wallwork.

Goals: Giggs 49.

Agg (3-1)

Att: 60,000

Ref: V M Pereira (Portugal).