Damien Duff's goal sealed Chelsea's passage into the Carling Cup final - as The Blues overcame Manchester United 2-1 at Old Trafford to give manager Jose Mourinho the perfect birthday present.

The Irish winger's curling cross left Tim Howard stunned as it beat everybody to find the far corner - and inflict a first ever domestic cup semi-final defeat on Sir Alex Ferguson.

Frank Lampard had handed Chelsea an early lead in this second leg - after United had held them at Stamford Bridge, but a nicely taken Ryan Giggs goal looked to have taken the game into extra time, before Duff's late winner.

The first half had been played at something approaching continental pace - with Chelsea scoring the first leg of the tie when an incisive break was started, and finished, by the ever impressive Lampard.

The England midfielder, cantering through the middle, picked out Didier Drogba and the French striker cut back inside and his intuitive pass went to Lampard's feet - allowing him to take a touch and finish clinically past Howard.

It had been a rare scoring opportunity as two quality sides warily weighed each other up,  circling like two prize-fighters through a languid opening period.

Louis Saha, ploughing a lone furrow up front for the hosts, showed signs of his quality when he ran swiftly into the Chelsea box, but stumbled under challenge from Makelele and had the good grace not to appeal for a penalty.

Lampard's goal illustrated Chelsea's pace on the break, but it was United who battled unsuccessfully to go into the break on level terms.

Ronaldo's weak free-kick showed that the Portuguese star has yet to add good decision-making to his stellar array of skills, but Quinton Fortune was unlucky not to be awarded a penalty when Wayne Bridge clumsily clipped his heels as he headed out of the penalty area.

At the other end Drogba, linking play with aplomb, dallied on an Arjen Robben ball, allowing Rio Ferdinand to rob him at the crucial juncture, and prevent The Blues from extending their half-time lead.

Soon after the break, the excellent Paulo Ferreira showed that Chelsea's quality is backed by the determination their manager has shown in spades, reacting brilliantly as Scholes raced onto a half-cleared Ronaldo cross to deny the former England international a major chance.

The arrival of Wayne Rooney roused the crowd, and soon after Roy Keane thundered a chance wide from a difficult angle.

Lampard drew a fine save from Howard when allowed space on the edge of the area, and the American produced an even better stop to deny Robben from close range after yet more quality play from Drogba, and a stepover from Tiago.

But suddenly the hosts were level - Giggs, playing a ball out to Gary Neville racing past John Terry and flicking the ball on and over Petr Cech as he raced out.

Mikael Silvestre was relieved soon after when his lax reaction to a ball through allowed substitute Eidur Gudjohnsen a half-chance that he could only help through to Howard, as the game finally opened up into something akin to an English cup match.

Howard had been exemplary throughout but the US international continued the horrific passage of goalkeeper errors that have haunted United's season when he was badly at fault for Chelsea's second.

Duff's free-kick from the right flank was curling wickedly in, but Howard simply failed to react as it went past everyone and nestled in the back of the net to the delight of the Irishman.

But for Bridge's goal-line clearance United would have got back level - Silvestre almost making amends for an untidy performance with a text book header from a corner that beat Cech but not the former Southampton man on the line.

Giggs tested Cech soon after, and the Czech Republic international then provided a stunning stop to deny Ronaldo's goalbound snap shot from the right of the area.

Mourinho was celebrating his 42nd birthday, and his players gave him the ideal gift with a committed, patient and ultimately deserved victory that takes them one step closer to an unprecedented quad of titles.

Teams:

Manchester United Howard, Gary Neville, Ferdinand, Silvestre, Heinze, Ronaldo, Keane, Scholes, Fortune (Rooney 59), Giggs, Saha
Subs Not Used: Phil Neville, Brown, O'Shea, Ricardo
Booked: Keane
Goals: Giggs 67

Chelsea Cech, Paulo Ferreira, Gallas, Terry, Bridge, Makelele, Lampard, Tiago, Robben (Cole 90), Drogba (Gudjohnsen 68), Duff (Jarosik 87)
Subs Not Used: Cudicini, Huth
Booked: Makelele
Goals: Lampard 29, Duff 85. Agg (1-2)

Attendance: 67,000

Referee: R Styles (Hampshire)

Manchester United	Team Statistics	Chelsea
1	Goals	2
0	1st Half Goals	1
5	Shots on Target	5
6	Shots off Target	3
5	Blocked Shots	3
5	Corners	6
10	Fouls	13
4	Offsides	3
1	Yellow Cards	1
0	Red Cards	0
79.4	Passing Success	75.1
53	Tackles	62
49.1	Tackles Success	62.9
57.7	Possession	42.3
55.6	Territorial Advantage	44.4