United topple Inter

The goals, both headers coming at the beginning of each half, saw Alex Ferguson register just his second career win over his old foe Jose Mourinho, whose Porto side eliminated United on their way to winning the tournament in back in 2004.

United moved into the last eight 2-0 on aggregate after the first leg in Milan ended goalless a fortnight ago, although Inter were far from pushovers and hit the woodwork in each half during an entertaining game.

But following their early breakthrough, United doggedly refused to allow Mourinho's side a route back into the game and the result ensured the holders retain an interest in the competition ahead of Friday's quarter-final draw.

As far as starts go, on the night United could not have asked for much better. Right from the kick-off they attacked Inter and they were rewarded with the opener from their second corner of the game.

Ryan Giggs's first dead ball had been easily cleared by the Italian defence, but his second found Vidic careering in unmarked to power a header past Julio Cesar.

The culprit for leaving the Serb all alone? A certain Patrick Vieira - a surprise inclusion in Mourinho's starting XI - the former Arsenal midfielder having turned his back and then slipped to leave Vidic free.

United then had two handball appeals in the space of seconds, the evergreen Giggs seeing a cross blocked by a prone Walter Samuel before Dejan Stankovic's arm got in the way of his second attempt to get the ball into the middle. While the first was the more plausible appeal, both were dismissed by referee Wolfgang Stark.

It was rousing stuff from the hosts but their initial fervour soon eased as Inter began to settle and gain a foothold in the game.

And sure enough, the Italian side began to create chances of their own, the mercurial Zlatan Ibrahimovic proving his goal threat on several occasions.

The Swede lost Rio Ferdinand to meet a free-kick with a downward header that bounced up on to the crossbar on 29 minutes before he fired wide having been put in by a sublime first-time pass by Mario Balotelli on 40 minutes.

In between those efforts, Stankovic brought a tremendous fingertip save from Edwin van der Sar before the Serb fired over with a difficult chance from Ibrahimovic's awkwardly bouncing cross.

At the other end, United had a glorious chance to double their lead before the first half was out, only it fell to the one man United fans would rather not have seen in such a position - John O'Shea.

The Irishman burst on to Wayne Rooney's delightful through pass but with Dimitar Berbatov free to his left he opted to go for goal, allowing Julio Cesar to narrow the angle and make the save.

Inter emerged from the tunnel for the second half rejuvenated and looking far more hungry than they had done 45 minutes previously.

But their gusto came to nothing as Ronaldo swooped four minutes after the restart, the Portuguese powering forward to meet Rooney's delightful cross and register his first goal of this season's competition.

Credit to Inter, they continued to search for a goal that would have got them right back into the game, Esteban Cambiasso bringing Van der Sar into action almost immediately after United's second went in.

Substitute Adriano, who had been demoted to the bench in favour of the disappointing Balotelli, then struck the inside of an upright with an outrageous flying volley that Van der Sar was struggling to reach.

But with that chance gone, Inter's game deteriorated - Ibrahimovic typifying the visitors' mood with a ballooned long-range effort before a half-hearted back-post attempt at a header - and with it went any hope of getting something from the tie.

Berbatov should have made it three for United following a Cesar spill and the Inter keeper had to be on his toes again to deny Rooney and then Ronaldo as time ran out.

The elimination of the Italian champions keeps alive the possibility of a quintuple for United, whose next task will be to beat Premier League pretenders Liverpool in Saturday's lunchtime clash.