After the two teams' goalless draw at San Siro, Champions League holders United proved their worth by overcoming the Nerazzuri 2-0 at Old Trafford.

Nemanja Vidic broke the deadlock as early as the fourth minute, before Cristiano Ronaldo secured his team a place in the quarters with a 48th minute header.

United took an early lead when Ryan Giggs' corner was met by a free header from Vidic that cruised past Julio Cesar.

The home side had two successive penalty claims waved away by the ref after Giggs' crosses touched Dejan Stankovic's then Ivan Crodoba's arms inside the box.

In the 27th minute, a Douglas Maicon free-kick from the right found its way towards Zlatan Ibrahmovic. The Swede's header bounced off the ground before clipping Edwin Van der Sar's bar.

Excitement reached its peak late in the first half when United looked keen on enforcing their lead as Inter were already pushing for an equalizer.

On 38 minutes, United produced a lovely move initiated by Giggs and Wayne Rooney to release John O'Shea through, but the Irish defender's low shot was blocked by Cesar.

Stankovic blazed his half-volley over after the former Lazio man was fed in the United box by a clever ball from Ibrahimovic.

Another chance went begging for Inter as Ibrahimovic fired wide from a tight angle from Mario Balotelli's through ball.

Sir Alex Ferguson's men took Jose Mourinho's team by surprise when they added a second early in the second-half.

Giggs, who was having an exceptional game passed to Rooney before Ronaldo beat Cesar to head the England striker's ball into the empty net.

Mourinho tried to boost his team's offense by bringing Adriano for Stankovic on 59 minutes.

The Brazilian almost made an immediate effect as he hit the post after meeting Esteban Cambiasso's cross with a bicycle kick.

Ronaldo could have added a personal second six minutes from time but the 24-year-old's free-kick was kept out by Cesar.

Watch the game's goals