Striker Andy Keogh scored two and made two as Wolves cruised into the fifth round of the FA Cup.
Wolves celebrate Bothroyd's goal
Keogh latched onto Jay Bothroyd's flick and chipped keeper Richard Lee to open the scoring, before Nathan Ellington hit the Wolves post with a free-kick.
Keogh supplied the pass for Stephen Elliott to make it 2-0 and then teed up Bothroyd for the third.
John-Joe O'Toole pulled one back by poking in following Steve Kabba's cross before Keogh netted from 12 yards.
Wolves always looked in control but ex-Watford man Darren Ward had to block Tamas Priskin's early effort and Kabba shot wide with the Hornets just one-down.
The second goal, which came on 58 minutes, was crucial.
It came after Keogh and Matt Jarvis played a one-two and Keogh then found Elliott, who made no mistake.
The tie looked over when Bothroyd beat Lee from close-range after Keogh and Jarvis had again been involved in the build-up.
After O'Toole's goal, Jobi McAnuff had a great chance to set up a tense finish as he got on the end of a cross from Watford substitute Tommy Smith, but he put his shot wide.
Keogh's second - a thumping shot after good work from Bothroyd - capped a fine performance by the visitors.
Watford: Lee, Doyley, DeMerit, Mackay (Mariappa 76), Sadler, Kabba, Bangura, O'Toole, McAnuff, Priskin (Smith 62), Ellington.
Subs Not Used: Poom, Stewart, Rinaldi.
Goals: O'Toole 70.
Wolverhampton: Hennessey, Darren Ward, Collins, Henry (Kightly 90), Foley, Rob Edwards, Potter, Jarvis (Gray 84), Elliott, Bothroyd (Gibson 90), Keogh.
Subs Not Used: Stack, Breen.
Goals: Keogh 5, Elliott 58, Bothroyd 68, Keogh 90.
Ref: Keith Stroud (Hampshire).
BBC Sport Player Rater man of the match: Wolves' Andrew Keogh 9.0 (on 90 minutes).
Please note that you can still give the players marks out of 10 on BBC Sport's Player Rater after the match has finished.