Cristiano Ronaldo had only one question left to answer in his flawless season - the whispered accusation that he had not delivered when it mattered in Europe.
It was a doubt that had the whiff of desperation from critics, and opposition fans, who were at pains to find a fault in the man who is currently the world's best footballer.
So it was almost inevitable that Ronaldo would be the catalyst for a United performance that underlined their credentials as Champions League favourites.
The facts back up the argument that Ronaldo is a key figure both at home and abroad - his goal against Roma was his 36th of a prolific season.
It was also his seventh in Europe this term to make him the Champions League's top scorer in the current campaign.
Ronaldo's heading ability is occasionally overshadowed by his dribbling skills and a happy knack of scoring goals of every type.
But his physique and spring make him a formidable force in the air, and it was a prodigious leap and header that set United on the path to victory against AS Roma in the Champions League last eight clash.
He also struck a post and volleyed just over in a performance that gave the lie to those desperate to pick holes in his extravagant gifts.
And Ronaldo's performance was symbolic of a United display that suggested the old uncertainties in Europe might finally be a thing of the past.
Given United's domestic successes in the last 15 years, one Champions League trophy is actually a meagre return for Sir Alex Ferguson considering the talent at his disposal and the opposition his team has faced in Europe.
Too many late stumbles. Too many defensive fragilities when placed under the unique pressures of Europe's elite competition. Too many missed opportunities.
There is no doubt this is something he is on a mission to put right in this year of all years - the 50th anniversary of the Munich air crash.
Those inside Old Trafford may feel the fates are on their side, but more importantly they have a team that is growing into the competition.
The attacking triumvirate of Ronaldo, Wayne Rooney and Carlos Tevez will always provide a threat, but a major development has been Rio Ferdinand's new-found maturity.
He was imperious in Rome, marshalling United's defence when the home side threatened a goal, especially once Nemanja Vidic was carried off after half an hour.
But it is Ronaldo, with the shadow of 1968's European Cup talisman George Best accompanying him, who represents United's greatest hope of winning the famous trophy for the third time.
And for those who had doubts about his European pedigree when they entered the Stadio Olimpico, they could banish them when it was time to leave.