SHAKY START
The English champions made a shaky start at the Stadio Olimpico and their Dutch goalkeeper Edwin van der Sar was lucky to get away with a risky early clearance.
Roma defender Christian Panucci then headed just over the bar from a corner in the 12th.
United tried to fashion a response but Brazilian midfielder Anderson hoofed their first effort well off target and Ronaldo drilled a long-distance freekick wide.
The hosts continued to look dangerous and Montengro striker Mirko Vucinic hit a powerful strike over the bar but it was Ronaldo who gave United the lead to stun the home fans.
Roma tried to respond and Vucinic squandered a superb chance to equalise with only Van der Sar to beat soon after the goal.
A determined Roma, who were without injured captain Francesco Totti, made a bright start to the second half.
Fullback Max Tonetto come close with a powerful effort and almost surprised Van der Sar with a cross-come-shot, while Panucci blasted over from short range.
Van der Sar produced a superb reflex save from a Vucinic header in the 62nd and United looked to be struggling before Rooney claimed his fourth goal in five games against Roma.
Ronaldo hit the post with a shot from outside the area and midfielder Michael Carrick nearly made it 3-0 with another long-range strike.
Rooney then struck the ball wide from a good position and Ronaldo volleyed just over as the home side began to lose heart in the closing stages.
(Agencies via Shanghai Daily April 2, 2008)