Dan Gosling's goal held up Norwich's coronation as champions, as well as pushing Watford to the brink of joining them in the Premier League.
The Hornets tightened their grip on second place with a 1-0 win, and still have to play Brentford and Swansea — who are challengers now more in hope than substance.
'From the first minute we showed high intensity, high ambition and I congratulate my players on their performance,' said Watford boss Xisco.
The visitors were the better team here, and fashioned five chances to open the scoring but Gosling failed to hit the target with three of them, including a free header from 10 yards.