Manchester United are clinging to a precarious lifeline in Europe after the slumbering giants of Juventus had been awakened in the tumult of Old Trafford last night.

In a game which rarely conformed to script, reports of the imminent demise of the Italian aristocrats proved just as misleading as suggestions that Zinedine Zidane's season had deviated irretrievably off-course. Operating with a heavily bandaged knee, Zidane dredged up enough of the skills which had illuminated France 98, to fire Juventus to quite their best European performance in this most erratic of seasons in Turin. United, often a distant second best in the opening 45 minutes, eventually salvaged their pride with a second-half performance which derived as much from passion as from the professionalism which earlier in the competition had been their badge.

Crucially, however, the Italians had by that stage plundered the away goal which threatens to hang like a millstone around Alex Ferguson's team when they had head to the return game in a fortnight. For all the intense pressure bubbling up in the visitors' penalty area, it wasn't until into injury time that Ryan Giggs eventually drove home an equaliser that had looked like eluding them for so long.

Before the game, Juventus' new coach, Carlo Ancelotti, had predicted that the team which triumphed last night would win the tie. And that assertion was reflected in the manner in which they set about pre-empting United's strategy.

Gone was the old, Italian stereotype of a big, massed defence. Instead, Juventus took on United at their own game and, for 45 minutes at least, won it hands down. Scorning the temptation to close up the game, they startled the crowd, if not the opposition, by taking an early stranglehold in midfield. And thus encouraged, they proceeded to dominate United in a manner which many of us believed unthinkable.

With the dynamic Dutchman Edgar Davids providing the link in some exquisite passing movements, they quickly tested the outer ring of the home defence. Davids, in the mood, rates as one of the great rallying forces in the modern game. And yet it was the elegance of Zidane which presented the home team with most of their problems in those torrid opening 45 minutes.

By contrast, Roy Keane and Paul Scholes regularly found the game by-passing them in that period. Keane, as ever, was competitive, and significantly it was his telling tackles which kept the team afloat at times when they appeared in imminent danger of being submerged. It was scarcely a surprise when Antonio Conte reduced the crowd to something approaching disbelief with the opening goal on 25 minutes. Davids' sleight-of-foot established the chance with a pass which took out United's central defenders and Conte slid the ball past Peter Schmeichel.

The lessons of that inept performance were not lost on Ferguson during the break, and by the time the teams reappeared Henning Berg had made his departure to be replaced by Ronny Johnsen. Whether by circumstances or design, Juventus played most of the second half on the back foot, and only then did the order of authority which Paolo Montero and Mark Iuliano radiated in the pivotal positions in defence begin to erode.

Keane directing the flow of attack down the left flank, United were suddenly reborn. Giggs, high on the list of United's best players on the night, at last found space, and if the quality of the crossing was never sufficiently precise to entice Juventus into serious error, the pressure continued to build by the minute. Keane, growing in influence, tested Peruzzi with a firm shot from 25 yards, and later Paul Scholes had a goal disallowed for offside, again from a chance created by the irrepressible Keane.

At that point Juventus were trading on luck as much as skill, but eventually, with a famous victory in sight, their luck ran out in the 92nd minute. Angelo Peruzzi, under pressure from substitute Teddy Sheringham, failed to make the decisive clearance from Phil Neville's cross, and when the ball fell at Giggs' feet he drove it exultantly into the net.

United were suddenly competitive again, but on the evidence laid out before a crowd of 55,000 last night, they still have a mountain of work to do to make it into the final for the first time in 31 years.

Manchester Utd: Schmeichel, G Neville, Irwin, Stam, Beckham, Cole, Giggs, Keane, Scholes, Yorke (Sheringham 78), Berg (Johnsen 46). Subs Not Used: Van Der Gouw, Butt, P Neville, Blomqvist, Solskjaer. Goals: Giggs 90.

Juventus: Peruzzi, Mirkovic, Montero (Ferrara 68), Conte, Di Livio (Tacchinardi 74), Inzaghi (Esnaider 87), Iuliano, Deschamps, Pessotto, Zidane, Davids. Subs Not Used: Rampulla, Birindelli, Amoruso, Tudor. Booked: Mirkovic. Goals: Conte 25.

Referee: M Vega (Spain).