It is rather too early to know the degree – and the depth – of Manchester United's latest renewal but we do know that their potentially toughest rivals endured more than the pain of late and demoralising defeat.
City – the team of ever more imposing financial muscle and stockpiled talent – had to reflect not on the intermittent brilliance of their conquerors but much more on their serially consistent state of mind.
More than anything, it houses an extremely belligerent reaction to the possibility of defeat.
This threat was put in place with much less beautiful intimidation than when Barcelona turned Wembley into their own playpen a few months ago but at 2-0, and with Yaya Touré beginning to look again like a midfield enforcer of formidable proportions, you wouldn't have put a lot of money on City failing to nail down their sudden advantage.
Indeed, for a little while Sir Alex Ferguson's expression said that some of his worst nightmares were coming to pass. He would need, you had to suspect, more than double-glazing to keep out the racket about to be generated by these particularly bothersome neighbours.
That it didn't happen had so much do with that way of thinking and, consequently, playing. United had not been so much put down as affronted and when Nani scored an equalising goal of quite brilliant conception and execution, when United swarmed around a defence which for a little while looked as efficient as it was mean, it was not Ferguson but Roberto Mancini who had most to worry about what might come to him in the next few weeks.
For the City manager, it is the old question. At what point does a collection of highly gifted and well-rewarded players begin to believe in its own weight as a team?
There was a flicker of encouraging evidence when David Silva fed in a beautiful free-kick to the head of Joleon Lescott, before Edin Dzeko profited from huge space and the uncertain reaction of David de Gea to his long shot. But then, as has happened so often at times of particularly compelling doubt, United simply ran through it. They continued to dictate the terms and did it with such confidence and panache that City were, as they had appeared to be in the opening minutes, quite lost.
Maybe the watching Sergio Aguero will implant a little more certainty in the next few weeks. Perhaps City will finally produce, before the close of the August window, the blockbusting signing that makes all the difference. Meanwhile, they remain a work in progress, impressive enough in their separate parts, but still short of a team who know quite what they might achieve.
United? They remain what they were while winning their 19th title in a less than vintage season – a team shorn of some classic strengths but still possessing, to a greater degree than any of their domestic and most of their foreign rivals, a quite remarkable competitive edge. Barcelona spelled out the new demands facing Ferguson in the last reach of his extraordinary career and no one could say that what we saw at Wembley yesterday constituted much more than a set of good intentions and a continued willingness to play to the edge of their ability.
Certainly, the first major appearance of Ashley Young must have brought a sharp degree of encouragement to the old warrior, along with the long-legged strides of Danny Welbeck, returning from his exile in the north-east frontier, and the impressive introduction of big Phil Jones, whose reassuring presence also ran to several forward passes of quite startling intuition.
Wayne Rooney produced an unspectacular but still seriously promising down-payment on his vow of a season of sustained graft and achievement, and Anderson also had moments of impressive intervention.
Did it add up to a tightening of the grip in which United held the Premier League at the end of last season? There was no such certainty – not least because the United player who made most difference, who turned the game and then carried it, at the expense of the normally relentless Vincent Kompany, was Nani.
Nani, who can, in the space of a minute, carry you across all the terrain of football from brilliance to absolute futility... Nani, who, when he came on in the Champions League final in May, almost as an after-thought, could occupy only the periphery of the game played by Xavi, Iniesta and Messi... Nani, who you can celebrate often enough but never quite trust.
Maybe he has turned a corner. Perhaps he will build on his thrilling audition for a new season. Yet still the suspicion has to be that United, certainly if they are to get a little closer to the old peak of Europe, need more sustained authority in midfield. Certainly their cooling on Wesley Sneijder must have more to do with economics than football need.
Still, there were plenty of reasons for United to leave Wembley with a level of optimism beyond their means after their last two visits to the stadium, when they were beaten by City in the FA Cup semi-final and relegated to another planet by Barcelona in May. They could tell themselves, once again, that there were the seeds of a new United, one which, with an average age of 22, had outplayed the powerbrokers from across town.
Tom Cleverley, who will be 22 this week, was no mean symbol of such hope when he came on as a substitute with an impressively combative edge. He was enraged by his failure to control a perfectly cushioned header to his feet by Rooney. Plainly, he had imagined his own breakthrough with a goal which would have been as finely shaped as Nani's equaliser. This, though, simply required Nani to complete his latest tour-de-force with his most decisive, killing moment.
Certainly it was too soon to know quite what it would all mean in the trenches of a new season. Beyond, of course, the latest evidence that United remain the team everyone has to beat.