There appeared to be only one winner at the interval after Dan Shittu had headed the Hornets in front, but Aidy Boothroyd's side seemingly got caught in two minds after the break, not sure whether to push on for a decisive second goal or protect what they already had.
In the end, they largely opted for the latter and the Canaries duly capitalised.
Watford made their intentions clear from the outset when Nathan Ellington blazed over after Tommy Smith had turned Mo Camara and pulled the ball back across the penalty area.
But set-pieces and the aerial prowess of centre-half Shittu have both been a major source of goals for the Hornets this term and it was no surprise when the two combined to positive effect in the 11th minute.
Jobi McAnuff, currently enjoying the best form of his Watford career, swung over a corner from the left and the Nigerian powerhouse rose highest to convert his ninth goal of the season from close range.
The only surprise after that was that the home side failed to convert their first-half supremacy into goals with Ellington, on more than one occasion and McAnuff going closest.
Norwich, in contrast, had relatively few forays into the opposition half and the best they could muster was a right-footed half-volley from Dion Dublin which Richard Lee was comfortably behind.
However, the complexion of the game was to change after the break.
The Canaries started the second period in far more positive fashion, with Dublin spurning reasonable opportunities after good build-up play by Lee Croft.
Boosted by that, the visitors grew in confidence, while the atmosphere around Vicarage Road became increasingly edgy with Watford's growing indecision.
That was found out after 81 minutes, when a Croft pass was met by a spectacular half-volley from substitute Cureton 18 yards out and Lee could only dive and admire as the ball flew past him.