Javi Gracia's side looked to play their part in the showpiece event at the national stadium as Roberto Pereyra broke clear of the City backline early on, and it proved to be a huge moment.
Had he scored, things may have been different, but he saw himself brilliantly denied by a trademark stop from Ederson, passing up what felt like a huge opportunity for the underdogs.
I’m a big fan of Roberto Pereyra has had a nightmare today— Piers Hanifan (@PiersHanifan) May 18, 2019
The Hornets were also aggrieved as they saw a penalty appeal waved away early on. Doucoure's shot inside the City box was blocked by Vincent Kompany, with the ball appearing to strike the Citizens' skipper's arm, but both Kevin Friend and VAR said no penalty.
Interesting VAR says no pen (I wouldn’t have given it) - CL VAR would have given it. No one knows the law.— Max Rushden (@maxrushden) May 18, 2019
If Watford were left to wonder whether they would regret spurning such an opening, they were absolutely right to do so. Just 15 minutes later, David Silva fired Pep Guardiola's side into the lead.
Remarkably, both Silva and Raheem Sterling won headers in the build-up against a physically commanding Watford backline, with the England forward's header into the path of his Spanish accomplice, and Silva did the rest with a clinical finish into the bottom corner.
Goalscorer David Silva but key man in that goal was Bernardo Silva. Winning back the ball like that off Doucoure in such a prime area of the pitch — Dean Jones (@DeanJonesBR) May 18, 2019
Things went from bad to worse for the Hornets, though, as City looked to seize further initiative and stamp a real authority on proceedings, and did just that as Raheem Sterling added the second before the interval.
Gabriel Jesus looked to have hooked the ball over the line from a tight angle, but Sterling arrived to force it home to help himself to the easiest goal he will ever score in a cup final. Watford were stunned, but in truth they had been the masters of their own downfall.
Huge fan of Sterling walloping it in from a yard out to try and steal a goal from a teammate. Brilliant shithousery.— Elliot Hackney (@ElliotHackney) May 18, 2019
There's a lot to like about Raheem Sterling.— Scott Saunders (@_scottsaunders) May 18, 2019
But the fact that he's willing to steal an FA Cup Final goal off his teammate by blasting it in when it's on the goal line means there's now even more to like about Raheem Sterling.
The second goal was a sucker punch for Watford, but City had little trouble in adding to their advantage and imposing their abundant superiority in the game.
Kevin De Bruyne was brought on early in the second half for Riyad Mahrez, and that was possible the worst thing that Watford could have hoped for, as the Belgian quickly set about stealing the show.
Watford were caught on the break once again, as Gabriel Jesus played in De Bruyne, who showed remarkable composure inside the box before tucking a simple finish past the stranded Heurelho Gomes.
Kevin De Bruyne Vs Watford— ⚽ = ❤ (@TheSporTalk) May 18, 2019
100% (40) Passes completed
4 Chances created
4/4 Long balls /completed
2/2 Dribbles / completed
THE MAESTRO #FACupFinal #MCIWAT pic.twitter.com/YDNwCsQ3Fh
De Bruyne given MOM award by sponsors. He came on ten mins into the second-half while Sterling has a hat-trick...— Mark Ogden (@MarkOgden_) May 18, 2019
Having been robbed of having his name on the scoresheet earlier on, Gabriel Jesus put his stamp on proceedings with a calm finish past Gomes following another lightning break from City, with De Bruyne pulling the strings once more with the assist.
Watford's heads well and truly dropped, but things got even worse for Gracia's side as Sterling continued to take the Hornets apart to seal it.
The City forward tucked away another simple finish following some good work from the ever-influential Bernardo Silva, before completing the rout with a rebound finish from his own initial effort, equalling the biggest FA Cup final win in history.
Not everybody was happy, though...
Language content: Man City fan gets into press box and complains about media covering Salah pic.twitter.com/mz2mm8J27n— Rob Harris (@RobHarris) May 18, 2019