Leeds went ahead in the 20th minute through Daniel James who took advantage of a terrible back pass from Edo Kayembe and James doubled the Whites advantage when finishing off a clinical counter eight minutes later.
A deflected Manor Solomon strike then put Leeds 3-0 up by the interval and a fourth goal arrived just after the hour mark through Joel Piroe after fantastic work from Ao Tanaka who ran in a circle to skin Tom Ince on the edge of the box.
Victory for Daniel Farke's side established a five-point advantage back to second-placed Sheffield United but also built a new eight-point cushion in the automatic promotion places back to third placed Burnley, albeit the Blades and Clarets have a game in hand.
Graham Smyth, the YEP’s chief football writer, hands out the scores from a rampant Whites display in the Tuesday night clash at Vicarage Road.
7. Ao Tanaka
8 - Composed on the ball for the vast majority of the game. Ran a ring around Tom Ince ahead of the fourth goal. Watford barely laid a glove on him. Photo: Richard Heathcote
8. Manor Solomon
8 - Dangerous throughout. Scored via a healthy deflection and it was from his pass that Piroe got the fourth. Photo: Zac Goodwin
9. Dan James
9 - Electric in the first half and so clinical. Beyond his goals he created danger. In the second half he continued to be impossible for Watford to handle. Photo: Zac Goodwin
10. Brenden Aaronson
8 - A very decent first half. Did really well in the move for James' second. Some lovely skill and dribbling in the second half. Not perfect around the final third but dangerous. Worked tirelessly. Photo: Zac Goodwin
11. Joel Piroe
8 - Played his part in the counter attacks that made Leeds so dangerous, set up James' second and after initially being wasteful, got himself a lovely goal. Photo: Richard Heathcote
12. Largie Ramazani (sub)
6 - A couple of glimpses of his quickness of feet. Selfishly opted for a shot from distance with team-mates ahead of him. Photo: Ben Roberts Photo