The relieved look of chairman Peter Ridsdale when Robbie Keane scored Leeds' face-saving second goal of the night to seal United's heart-stopping passage through to the third round of the UEFA Cup said it all.

At 3-1 down and with 13 minutes remaining, Leeds were staring at an embarrassingly early exit from the competition just seven months after reaching the semi-finals of the Champions League.

The hopes and dreams of Ridsdale, manager David O'Leary and his squad assembled at a cost of £86million during his three years in charge were hanging by a thread.

Keane cost £13million of that figure and never has every penny seemed so worthwhile than when the Republic of Ireland international headed home the goal to spare the blushes of everyone connected with the club.

In truth, Leeds should never have been in such a precarious position for the tie should have been over as a contest following the first leg at Elland Road given United were strolling at 4-1 at one point, and against 10 men.

But complacency again set in and instead of looking to finish off Troyes, they took their foot off the gas and conceded what was clearly at the time a worrying second to two-goal Patrice Loko.

To add to O'Leary's worries, he was without the influential presence of skipper and centre-back Rio Ferdinand due to a hamstring strain sustained in the 1-1 draw against Manchester United on Saturday and aggravated in training 48 hours later.

With Jonathan Woodgate involved in a retrial at Hull Crown Court and Lucas Radebe not having played this season due to a knee injury, it led to Michael Duberry being drafted in for his first start for almost 14 months.

Even then Duberry only played after passing a late fitness test on an ankle injury sustained in training last night, a session missed by midfielder Eirik Bakke due to a knee problem, but the Norway international also received an 11th-hour call up.

With Lee Bowyer, like Woodgate unable to travel due to the court case, O'Leary fielded his strongest possible line-up, one which should still have proved too strong for Troyes despite their remarkable 'Wimbledon-esque' rise through the French League system over the past few seasons.

But it just took eight minutes for the unthinkable to happen as Leeds conceded the opening goal of the night, Gharib Amzine connecting sweetly with a Loko corner, the Morocco international's first-time 25-yard strike curling away from Nigel Martyn into the top left-hand corner.

Parity and United's two-goal aggregate cushion was restored just six minutes later as Mark Viduka powered a header past Tony Heurtebis after the Troyes goalkeeper could only touch on an Ian Harte corner, allowing Bakke and David Batty to set up their Australian team-mate.

It was his sixth goal of the season, his fifth in the last six games and proved the catalyst for Leeds to then take control, with Troyes looking increasingly fragile at the back.

Keane was twice denied, first by Mohamed Bradja on the line and then a smart save by Heurtebis, before being accused of handling by Italian referee Massimo de Santis to rule out a superb 18-yard Harry Kewell lob.

It then took an unfortunate deflection off Dominic Matteo to restore Troyes' lead, the Scotland international's touch to a David Hamed 25-yard free-kick seven minutes from the break wrong-footing Martyn.

The goal visibly lifted coach Alain Perrin's side going into the break at the end of which Leeds were without another key player in Kewell, the Australian international replaced by Jason Wilcox.

It came as no surprise when Troyes grabbed the third in the 58th minute with Jerome Rothen sweeping home Rafik Saifi's goal-line pull back after having beaten Duberry.

With Leeds looking short on confidence and ideas, Troyes should have added a fourth as they staged a breakaway to near devastating effect, with Hamed and Rothen setting up an all-alone Loko.

But with only Martyn to beat, the former France international somehow lofted his shot over the bar and it proved the let off Leeds needed for they grabbed that vital second in the 77th minute.

Batty picked up a clearance and fed Viduka whose ricocheted cross found Keane to head home his seventh goal of the season - and none more important since his arrival from Inter Milan last December.

Even then it took a brilliant point-blank block by Martyn in denying Nicolas Gousse in the dying seconds of injury time to prevent extra time, moments prior to de Santis bringing the curtain down on a thriller with the final whistle, at which point Ridsdale let out an exasperated sigh of yet more relief.

Teams

Troyes: Heurtebis, Boutal, Olivier Thomas, Saifi (Gousse 74), Hamed, Rothen, Bradja (Adam 81), Tourenne, Amzine, Loko, Danjou.

Subs Not Used: Sekli, Jbari, Leroy, Niang.

Booked: Olivier Thomas, Hamed.

Goals: Amzine 8, Hamed 38, Rothen 58.

Leeds: Martyn, Mills, Duberry, Matteo, Harte, Bakke, Dacourt, Batty, Kewell (Wilcox 46), Viduka, Keane.

Subs Not Used: Robinson, Kelly, McPhail, Smith, Burns.

Booked: Batty, Dacourt, Wilcox.

Goals: Viduka 14, Keane 76.

Agg (5-6)

Att: 14,500

Ref: M De Santis (Italy).