Manchester United took a slender lead in their UEFA Champions League quarter-final with Chelsea as Wayne Rooney scored the only goal of the first leg at Stamford Bridge.

Rooney's foul-mouthed celebration after scoring a hat-trick at West Ham on Saturday may have landed him in hot water with the Football Association, but he carried on his fine form against Chelsea with an away goal for United to take back to Old Trafford for the return match next Tuesday.

The crucial moment arrived midway through the first half when Ryan Giggs superbly controlled a long pass from Michael Carrick and cut the ball back for Rooney to slide home a composed finish that went in off the post.

Chelsea almost equalised on the stroke of half-time as Fernando Torres guided an effort against the post and Frank Lampard's volley on the rebound was cleared off the line by Patrice Evra.

Torres went close again in the second half but still could not open his account for the Blues as Edwin van der Sar pulled off a magnificent acrobatic save to claw out his well-placed header.

United had to withstand spells of Chelsea pressure, particularly in the closing stages, when confident penalty appeals for a foul on Ramires by Evra were waved away, but were largely comfortable in keeping them at bay and occasionally threatened on the counter-attack.

Ecstatic

Chelsea will nevertheless travel to Manchester with the tie still in the balance. Indeed, a repeat of the 2-1 success on their last trip to Old Trafford 12 months ago will be enough to send them through.

However, they will have to do far better in front of goal - and £50million man Torres in particular must start scoring after yet another ineffective display ended with an injury-time yellow card for diving.

At Upton Park on Saturday, Rooney completed his hat-trick, then headed straight towards a TV camera to deliver his ill-advised reaction that threatens his place in the FA Cup semi-final with Manchester City.

As his first-time effort caressed the base of Petr Cech's left-hand post and rolled gently into the back of the Chelsea net, he again ran towards the lens.

This time, he stopped short, slid to his knees and waited to be mobbed by ecstatic team-mates.

They had every right too, especially Giggs given his outrageous contribution. Now 37, Sir Alex Ferguson has claimed the veteran Welshman could go on for a couple of years yet.

How the United boss must hope that is true. Having watched Michael Carrick deliver a pinpoint crossfield pass that was sensational in itself, Ferguson could only sit back and admire Giggs' sublime first touch, which took him careering past the stranded Jose Bosingwa, and the coolness of his second, which left Rooney with a tap-in.

Cue delirium amongst the United contingent, satisfaction for Rooney and the precious away goal Ferguson had demanded.

Carlo Ancelotti could only urge his team - who had started the brighter - into some kind of response.

It should have come in the final minute of that opening period as Didier Drogba went for goal from an acute angle but his shot lacked power.

Torres closed in, yet somehow could not make a meaningful connection on the ball from a central position on the edge of the six-yard area.

As the ball bounced back off the post, Lampard went to tap home, only for Evra to clear off the line.

Given Saturday's draw at Stoke and Inter Milan's stunning demise to Schalke on Tuesday, it is hardly overestimating the situation to say Carlo Ancelotti's job hangs on reaching the final, and for that Torres needs to do what Roman Abramovich paid all that money for.

Hammer blow

United suffered a hammer blow within minutes of the restart when Rafael went down after a seemingly innocuous tangle with Drogba.

The young Brazilian bravely tried to continue but the pain in his left knee made it impossible, the stretcher carrying him away for what looks like a lengthy period.

Ferguson's response was typical. With no obvious right-back replacement, instead of introducing a defender, in Chris Smalling or Jonny Evans, he went for Nani, asking Antonio Valencia to plug the gap.

Chelsea were able to get up a head of steam though, with Ramires wasting an excellent chance when he glanced Drogba's effort wide of the far post and the Ivorian himself not too far away with a speculative overhead kick.

United's defence - which has not conceded an away goal in this competition this season - held firm and came agonisingly close to grabbing a second when Nani drilled a cross to the far post that would have allowed Javier Hernandez to head into an empty net had Cech not gambled in a desperate attempt to claw the ball away from the Mexican.

The departure of Drogba for Nicolas Anelka 20 minutes from time placed even more weight on Torres' shoulders just after Michael Essien had gone close for the hosts.

And the Liverpool man so nearly responded when he rose to meet Jose Bosingwa's far-post cross and sent a header curling towards the corner that Van der Sar, troubled by a groin problem, was at full stretch to claw away.

United then breathed a sigh of relief in stoppage time when Evra sent Ramires tumbling but referee Alberto Mallenco failed to award what seemed to be a clear penalty.

There was still time for a Torres yellow card for diving under Valencia's challenge, ending yet another unhappy night for the Spain star.

Chelsea	Team Statistics	Manchester United
0	Goals	1
0	1st Half Goals	1
7	Shots on Target	2
8	Shots off Target	1
6	Blocked Shots	5
3	Corners	5
15	Fouls	17
2	Offsides	3
4	Yellow Cards	2
0	Red Cards	0
83.9	Passing Success	73.1
16	Tackles	29
87.5	Tackles Success	69
57.2	Possession	42.8
55.4	Territorial Advantage	44.6

Click Here for Official Teamsheet

Teams 

Chelsea  Cech, Bosingwa (Mikel 79), Zhirkov (Malouda 71), Ivanovic, Terry, Cole, Ramires, Lampard, Essien, Drogba (Anelka 71), Torres
Subs Not Used  Turnbull, Benayoun, Ferreira, Kalou
Booked  Zhirkov, Ramires, Essien, Torres
Goals 

Manchester United  Van der Sar, Rafael (Nani 52), Ferdinand, Vidic, Evra, Valencia, Carrick, Park Ji-Sung, Giggs, Hernandez (Berbatov 78), Rooney
Subs Not Used  Kuszczak, Smalling, Scholes, Evans, Gibson
Booked  Vidic, Van der Sar
Goals  Rooney 24

Attendance  37,915

Referee  Alberto Undiano Mallenco (Spain)