Experience, desire, and confidence gave Manchester United an advantage over a Roma team without its leader, Francesco Totti.
With the Italians short-handed, with Juan, Simone Perrotta and Francesco Totti all missing, Manchester played a patient waiting game before Cristiano Ronaldo headed the ball past the helpless Doni as the half-time whistle approached.
The game was so tight until the 43rd minute. Roma's players were sucked into their own half, which was orchestrated beautifully by Paul Scholes and Michael Carrick.
The Italians allowed the visitors to gain possession patiently for most of the first half before the advancing Wayne Rooney smartly got rid of his marker and slipped the ball to Paul Scholes out on the right.
With the entire Roma defense blindly following Rooney, Cristiano Ronaldo raced into the penalty box unnoticed to blast a powerful header past Doni. Forced to chase the game from then on, Roma left themselves exposed to United's striking counter-attacks.
The Roma side looked confused, haphazardly launching attack after attack, essentially producing nothing.
With Totti out for the game, all eyes were on the Brazilian star Mancini who supposedly should have played Totti's role on the field. He looked absolutely lost on the field which allowed Mirko Vucinic to take advantage of working hard to produce a goal with every possession, but it did not end brightly.
After weathering another storm at the start of the second half, the Red Devils killed off the match, and most probably the tie, when striker Ji-Sung Park headed the ball to Roma's goalkeeper only for the ball to slip out of his hands and into Rooney's feet for the final goal of the game.
Now the leading scorer in the competition with seven goals, Ronaldo's reckoning for the season as a whole stands at 36.
As the unstoppable forward continues to sweep, his recently stated aspiration to become the best player in the world comes ever closer to fulfilment.
Manchester United are close to advancing to the Semi Finals, but can Roma get back in the tie?
Last year, Roma won 2-1 at Stadio Olimpico and were heavily blasted seven goals to one back at Old Trafford. This year so far, the opposite is in effect with Manchester currently two goals ahead of Roma.
This does not mean that Roma will earn a victory equivalent to United's at Old Trafford, but Roma could produce an upset back in England.