This was not a contest, this was an exhibition. This was not a match, this was a mismatch.
And this is why the pressure is on Pep Guardiola like it is on no other.
Fail to win the Premier League title with this startling array of attacking talent and it will be an under achievement.
Simple as that.
Guardiola has had his foundation year, his learning curve – this season holds no excuses.
How can it when he has assembled a collection of the quickest-passing, sharpest-thinking individuals the Premier League, possibly, has ever seen?
When Guardiola decided that Nicolas Otamendi’s header for the fourth, just after the hour mark, had put a formal end to this brutally lopsided affair, he gave a run-out to Bernardo Silva, Ilkay Gundogan and Leroy Sane. Because he can. Three world-class talents getting a few minutes in the final throes of a walkover.
There you have City’s astonishing, forward-thinking depth.
Watford worked honestly, created the odd chance, but, essentially, were little more than cones in a practice session.
Do not let anyone tell you there are no easy matches in the Premier League and this, remember, was against a team unbeaten in their first four fixtures.
Brilliantly, some Watford players ended their afternoon of pursuing shadows by haranguing referee Anthony Taylor.
What for? Blowing the first whistle? Playing added time? Or because he was the only person they could keep up with? Marco Silva was correct to point out goals one and three had more than a suspicion of offside about them.
Taylor and his assistants did not have great days.
But no flag or whistle would have made a difference to the outcome.
It was Playstation stuff, a hammering of the highest order.
If this is what Pep preaches, his gospel is welcome.
It was hallelujah football.
Again, the modern truth is that passing pyrotechnics such as these will mean nothing if defensive inadequacies continue to surface.
Before Sergio Aguero firmly nodded home instalment one of his hat-trick, Richarlison actually had a free header from six yards.
It probably would have been the difference between 0-6 and 1-6, but it was a City flaw all the same.
To dwell on flaws for longer than a moment, though, would be an insult to a quite imperious body of work.
It was hard to flick your gaze quickly enough to do each contributor justice.
Inside a stunned Vicarage Road, the emphatic thud of first-time passing assailed the ears.
This display even sounded good. Trust me.
Kevin De Bruyne was almost too good to be kicked, even though Jose Holebas tried his best.
The assist for Aguero’s first was from De Bruyne, the assist for his second was from David Silva, who probably reverse passes the salt at dinner-time. Aguero’s selflessness swells by the game, which is some feat, considering he remains ravenous for goals.
His third – City’s fifth – was a typically wriggling, individual effort. The most underappreciated Premier League striker of his generation even had time to set up another for Gabriel Jesus and allow Raheem Sterling to wrap up proceedings with a penalty.
Considering Sterling had earned it, fair enough.
The selfless approach and the camaraderie comes easily when you are winning plenty to nothing in game after game.
And there is no doubting the joy coursing through this City team right now.
Tests of character will come, the pressure that comes with being part of such an expensively assembled, lavishly gifted squad will grow.
That is for sure and Guardiola knows it, knows that performances like this show there is no room for excuses this season.
But, then again, if everyone wants to just enjoy this for a while, they should.
It was special.