Manchester United 3 Benfica 1: United sail on with all cannons blazing after Nelson broadside

A Portuguese winger called Nelson almost inflicted a second successive Champions' League catastrophe on Manchester United last night but it is at times like these that Sir Alex Ferguson expects that every man will do his duty. And their duty last night, with their European campaign on the brink of oblivion, was to put on a performance that was a throwback to the glory nights of Old Trafford eight years ago.

It was the classic United plot, a night that was made for a heroic comeback although when Nelson Augusto Tomar Marcos's shot ripped into Edwin Van der Sar's goal on 27 minutes a shudder went round the stadium. This was the abyss of Champions' League elimination that United were contemplating for the second year in succession and the doomsday financial scenarios it entails. In the directors' box, David Gill must have wondered how he would explain the point of the Uefa Cup to the Glazers.

This time, however, Ferguson's players saved him the humiliation. It is one of the curiosities of this team that they needed to be terrorised by a Benfica goal into taking control of the game. In fact, they attacked throughout the end of the first half, as if they had convinced themselves the game was due to end at half-time. That or they just could not face Ferguson at the interval one goal down.

In the frenzy of the end of the first half, before Nemanja Vidic equalised on the stroke of half-time - and before Ryan Giggs and Louis Saha added the others in the second half - United were freed from the constraints of a 4-3-3 system that too often became 4-5-1. Rooney was once again abandoned to the left and only when he was sent up front to accompany Saha did United come to life.

Ferguson did not elaborate on that crucial change, although surely no one needs any more persuading that his team are so much better as a 4-4-2 formation. Instead he said that United could "thank Mr Nelson for the goal - then we saw the real Manchester United". United finished the night at the top of Group F, but for 20 minutes it could have been very different.

Almost a year on, Ferguson's January signings are starting to look worthy of the first team. Patrice Evra was selected ahead of Gabriel Heinze and Vidic, even without his goal, was a candidate for the game's outstanding performer. It is on the bench that United seem to lack the menace to win the competition. Given that Ferguson still does not believe Alan Smith is fit enough, much will rest on the effect of Henrik Larsson when he arrives in January.

Poignantly, one potential opponent for United in the next round is Real Madrid who finished second in Group E. How ironic it would be if David Beckham was to return to Old Trafford - most probably as a substitute - almost three years after Ferguson relegated him, as a United player, to the same lowly status when Real last visited.

What United opponents in the next round learnt last night was that it pays to be daring against them. Benfica's coach, Fernando Santos, had, befitting a manager who had to win, tried something a little more daring, with Simao lurking behind a front two of Fabrizio Miccoli and Nuno Gomes. They caused United problems and then, on 26 minutes, crafted a fabulous goal.

It began in the centre of the pitch when Nuno Gomes controlled a knockdown and volleyed the ball wide to the right wing where Simao cut in. He jinked outside Evra and passed the ball back to Nelson, on the edge of the are,a who dispatched a devastating drive.

The winger had been the chief architect of United's demise in Lisbon one year earlier but this time United responded. Ronaldo struck a dipping free-kick that was tipped over and then Nelson appeared to handle Saha's effort on the line. Vidic made a tackle on Nuno Gomes that threatened to put the game out of sight and Rooney was booked for dissent.

Eventually the breakthrough came when Simao tripped Ronaldo. The free-kick, struck from the left side of the area by Giggs, found Vidic, who climbed the highest to head home the equaliser. It was to United's credit, however, that they did not relent. Gary Neville was impressive on the right flank, driving his side forward. On 61 minutes, Ronaldo struck a right-sided cross that met Giggs' run on the blind side of Nelson perfectly and the winger directed his header past Quim.

On 75 minutes, Ronaldo thought he had won a penalty when Petit's lunge in the box did not connect with the ball. All he got was a corner, which Paul Scholes curled on to the head of Saha for the third goal. The Frenchman might not quite have earned redemption for his collapse of nerve against Celtic last month, but last night went some way to healing a few old wounds at Old Trafford.

Manchester United (4-4-2): Van der Sar; Neville, Ferdinand, Vidic, Evra (Heinze, 67); Ronaldo, Carrick, Scholes (Solskjaer, 79), Giggs (Fletcher, 73); Saha, Rooney. Substitutes not used: Kuszczak (gk), Brown, O'Shea, Silvestre.

Benfica (4-3-1-2): Quim; Nelson, Luisao, Ricardo Rocha, Leo; Katsouranis, Petit, Nuno Assis ( Karagounis, 73); Simao; Nuno Gomes, Miccoli (Paulo Jorge, 64). Substitutes not used: Moretto (gk), Anderson, Mantorras, Miguelito, Beto.

Referee: H Fandel (Germany).