In the endgame of Europe and the Premier League we had this week one supreme moment of authority, one piece of evidence that is hard to reject when we consider who has best gathered and released his forces and is most likely to be the big winner.
Choreographed by the apparently evergreen Paul Scholes, executed with a timing and power remarkable even by the standards of Cristiano Ronaldo, it said that Sir Alex Ferguson may now be mining the richest vein of all his years at Old Trafford.
Scholes' exquisite chip into the unstoppable path of Ronaldo, and then his matador gesture when his young team-mate thundered home a header guaranteed to break the heart of a better team than Roma, encapsulated so much of Ferguson's strength, and most of all the depth and range of his squad.
Scholes, after another bout of injury, seemed to be losing his battle to withstand the challenge of such young blood as Anderson, Michael Carrick and Nani a few weeks ago, but now his game sang with such bite and vision it confirmed the most cynical reaction to Ferguson's claim that if United reached the final he might just pick his most consistent player over the years out of sheer sentiment.
In matters of win and loss, Ferguson is of course about as sentimental as a debt collector on piece rates. You have to believe that he made his statement only after he saw that Scholes was coming yet again.
No, the prize for sentiment – if little other practical reward – surely goes to Arsène Wenger.
While Scholes underlined the Ferguson options so brilliantly, 24 hours later Wenger's potentially luminous midfield of Cesc Fabregas, Mathieu Flamini and Alexander Hleb seemed, ultimately, to have been stretched a little too far.
It is outrageous that Arsenal do not carry a 2-1 lead into their second leg at Anfield next week – if Dirk Kuyt didn't foul Hleb in close proximity to the referee we might as well accept that arm-wrestling has become an integral part of the beautiful game – but if they were overall the better, more imaginative team, there is no question that at times they were also one at their limits.
Now Wenger is talking, rather wistfully, about his legacy not depending on the underpinning of a Champions League triumph. He is also reflecting on the irony that it was arguably his greatest invention, Thierry Henry, who twice failed to pull the trigger in optimum circumstances in the final in Paris two years ago. Yet if Wenger is right that the memory of his Arsenal years will endure as long as there is somebody around to swear to their quality, he is just as surely wrong not to accept that while Ferguson's teams have not exactly lacked for brilliance, they have also been girded far more strongly of late for the longest, hardest campaigns.
The suspicion must be that Wenger's wonderful idealism on the matter of how the game should be played, and how it can be mastered if you have enough belief in your methods and the quality of your playing roster, has been undermined this season in a way that Ferguson would never countenance.
Owen Hargreaves, Nani and Anderson have been added to a midfield groaning with individual ambition – Fabregas and Flamini have been operating against the dread that either of them are struck down before any significant game.
Though Arsenal drew some beautiful patterns against the pragmatically deployed Liverpool resources of Rafa Benitez, they always seemed to be searching a little too hard for the power that United so easily conjured at the decisive moments in Rome. There was also the huge hole left by one of Arsenal's players of the season, the right-back Bacary Sagna. Emmanuel Eboué having become discredited at full-back, as in most other positions on current form and demeanour, Wenger was obliged to weakened his central defence against the potent threat of Fernando Torres and Steven Gerrard by moving Kolo Touré on to the flank. At United these days such adjustments are made with hardly a hint of a seam.
It means they must go into next week's action the strongest of favourites to gain a place in the semi-finals, against a Barcelona desperate for the return of Ronaldinho and Lionel Messi to fitness.
Liverpool, given their European pedigree and their cool willingess to ride some good fortune at the Emirates, will be rated not so far behind by many, but the truth is that it was only Ferguson's team who made a totally convincing case for their prolonged, and eventually successful, involvement.
Despite their leaden performance in Istanbul, Chelsea's ability to beat Fenerbahce at Stamford Bridge by the minimum requirement of 1-0 cannot be seriously questioned, for they are closest to United in the depth of their strength, if not their inspiration.
So what is it that can stop United beyond the resurrection of Ronaldinho and Messi, hungry and effective, later this month? Maybe it is the one flaw in Ferguson's European armoury, the perception, on some occasions more obvious than others, that he feels obliged to tinker with his team's essential strength of strong and creative football. His dogged view is that there are two games, one to be played against Premier League opposition, another against Europe. It is a belief that has cost him in the past, but then maybe the sight of Scholes and Ronaldo combining so perfectly will have reminded him of an old and unassailable football truth.
It is that if they are good enough, players not tactics win games. For his part, Wenger will go to Anfield believing his players can do to Liverpool what they recently did to Milan. Despite the pressure many will say he has brought on himself, it is still a little early to dismiss his dream. Never mind the width, look at the quality, he says, and it is not as though his suit is in tatters.