Vakoun Bayo's late breakaway goal earned victory for Watford and left managerless Norwich City pondering a dismal home run which has now seen them win just once in nine Championship matches at Carrow Road.
Bayo tapped the ball home after a slick move, Ismaila Sarr racing away down the left and showing great composure to pick out the striker to net from close range.
Watford had been the more threatening for much of an entertaining game, with the impressive Keinan Davis twice going close before the break.
But the Canaries, in their second game under interim boss Allan Russell, improved in the latter stages and twice threatened through Adam Idah, only for Bako's effort to ensure the Hornets move up to fourth in the Championship table and leave Norwich languishing in 11th place.