The Premier League champions had already qualified top of Group F after five wins from their opening five games and went ahead through Gerard Pique's 34th minute header. Sir Alex Ferguson made nine changes to the team that beat Derby County 4-1 at the weekend, and his young team nearly held on for what would have been a memorable victory at the Stadio Olimpico. But Brazilian forward Mancini beat Wes Brown and whipped a fierce curling shot past Tomasz Kuszczak to save Luciano Spalletti's blushes in Rome.
Manchester United boss Sir Alex Ferguson on his young side's display:
"I was pleased with a lot of it, it was a very good experience.
"There wasn't a great deal at stake but both sides played with freedom and good expression and it was a good contest.
"We lacked experience at times but made up for it with ability on the ball and we can be happy against a strong team."
Fergie on Pique:
"He's good in the air, well he is a tall lad but it's good to see"
Roma: Doni, Cicinho, Ferrari, Mexes, Barusso (Giuly 62), Antunes, Pizarro, Esposito (Vucinic 62), Taddei (De Rossi 46), Mancini, Totti.
Subs Not Used: Bertagnoli, Panucci, Juan, Pit.
Goals: Mancini 71.
Man Utd: Kuszczak, Simpson, Pique, Evans, O'Shea (Brown 54), Eagles, Fletcher, Carrick, Nani, Saha, Rooney (Dong 71).
Subs Not Used: Heaton, Lee, Hewson, Brandy, Eckersley.
Goals: Pique 34.
Ref: Martin Hansson (Sweden).
Man of the Match: Gerard Pique Handled the classy Roma forwards with composure and scored his second goal for United in Europe this season.