Ronaldo, who is cup-tied in the Champions League, led a largely reserve team to victory with goals in the 14th and 69th minutes.

David Suazo narrowed the gap in the 74th minute with a penalty but Andrea Pirlo netted five minutes later to secure all three points which allowed Milan to hold onto fourth place in Serie A and focus all of their efforts on United on Tuesday.

Milan lost Kakha Kaladze to a red card five minutes from time for a second yellow card.

Milan coach Carlo Ancelotti named a much-weakened side with a trip to Old Trafford playing on his mind.

Only Gennaro Gattuso and Clarence Seedorf were the two stars not given a rest while Alessandro Nesta, Kaka, Paolo Maldini and a host of other big names watched on from the sidelines.

There may have been a huge personnel shift, but the desire to win remained the same.

Seedorf and Ricardo Oliveira both got in each others way as the first chance arrived after 12 minutes.

Just two rounds of the clock later and the home side were ahead.

Cafu went in dangerously on Cristiano Del Grosso, but he emerged with the ball and space to explore.

Ronaldo was waiting in the middle and his compatriot duly laid the ball on a plate for his sixth goal of the season.

Goal number seven loomed for Ronaldo as he played a neat one-two with Seedorf, but Diego Lopez made a fine last-ditch tackle to clear the ball behind for a corner.

Cagliari were struggling to find a way through the massed ranks of black and red shirts and their best, if not only route, was over the top, using the pace of Suazo.

Only once was the Honduran able to beat the last defender, however, and on that occasion, Zeljko Kalac had raced from his goal and cleared the ball first.

Milan could then have gone into the break two goals to the good as Yoann Gourcuff crossed for Oliveira, but he did not manage to divert the ball past Antonio Chimenti.

The game opened up in the second half with Cagliari beginning to find ways through the Milan defence and the home side moving up a gear to compensate.

And once again, it was the Brazilian connection which doubled the Rossoneri advantage.

Cafu provided the cross from the goal line and Ronaldo did not even attempt a header, opting instead to use his chest for an extraordinary goal from six yards.

Cagliari's reaction was immediate with Suazo racing through but Kalac once again reached the ball first.

Suazo then provided Andrea Capone with a chance but he was tripped by Kaladze inside the area and the penalty was given.

Suazo this time got the better of Kalac, sending the Australian the wrong way from the spot.

However, the visitors were not back in the game long before substitute Pirlo sent in a magnificent direct free-kick from 25 yards which arched into the top corner beyond the reach of Chimenti.

Kaladze picked up his second yellow card for another foul on Capone late on, leaving Ancelotti with one man less to choose from when he next plans to rest his big guns - probably next weekend against Torino.