Javier Hernandez, the young man with the matador's finish, fell the wrong side of another penalty controversy last night, but had he been rewarded with more than a yellow card for diving we would have this morning another reason to acknowledge one of most insistent winning instincts in English football.
There would have also have been the mother and father of refereeing rows. Enough to say, maybe, that however exaggerated the Mexican's reaction there seemed to be clear contact by the outstretched leg of defender Danny Simpson. However, United had no reason to argue that they were denied the spoils they deserved.
In fact, this was a flashback of a non-vintage season for the Champions-elect. They were required to dig in at Newcastle and do those things which have been required of them for most of a frequently improbable pursuit of the unique mark of 19 titles.
You can put most of these hard chores into the catch-all category of survival and it was clear enough last night that Manchester United would have to run through the full gamut. Newcastle had everything but a killer stroke.
They played with a vigour, a width and a relish for the battle which was a tribute to their manager Alan Pardew's ability to produce evidence of serious purpose in a place which until his controversial arrival had become the running joke of English football.
It was also a pressure on United that Joey Barton seemed intent on seizing this large stage to make his point that without his litany of past crimes he would be occupying a much higher place in the pecking order of England midfielders. Some of his passing and all of his bite in the first half, particularly, certainly gave a little weight to some of his recent trumpetings.
But if he and Jonas Guiterrez stretched United almost to breaking point they were soon enough reminded of the nature of United's latest title challenge. It is about the need to supplant any shortfall of inspiration with the instinct to fight from one scuffling battle to another.
As at Wembley last Saturday, the league leaders were unable to generate the bite in front of goal that would have carried them another stride in the failed pursuit of a treble.
That they will retain the resilience, the gut-deep resolve to hang on, is something that Arsenal will be conscious of when they seek to reanimate their own challenge at White Hart Lane tonight.
United were desperate in the end and when Sir Alex Ferguson talks of an overhaul in the summer he will surely be seeking something of more authority than was on hand at the vital moments last night.
Ryan Giggs has made a sensational contribution to this extraordinary campaign but, as with his old fellow warrior Paul Scholes, there is plainly a running down of the sustained ability to inflict a consistent cutting edge.
If United do make it past the line – and they remain 1-6 favourites – it will be more than anything a tribute to their unwillingness to concede a yard in the most pressing of circumstances. Giggs, of all people, had the best chance to gather in three more points and his effort went just inches wide.
Had he scored, of course, we would be would talking of another march to glory. Instead, the race remains at least to some degree unresolved. If United get there, plainly they will be required to take a different form in the summer months.
Meanwhile, they are obliged to do what they have again proved themselves eminently capable of. They will continue to slug it out.