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.
13. Willy Gnonto (sub)
6 - Couldn't quite carry on where James had left off but the game was done and Watford managed to keep him quiet. Photo: Matt McNulty
14. Joe Rothwell (sub)
N/A - On for the final 10 minutes, busied himself. Little in the way of noteworthy moments. Photo: Ben Roberts Photo
15. Mateo Joseph (sub)
N/A - Struggled to get himself involved. Hassled defenders. Photo: Stephen Pond
16. Pascal Struijk (sub)
N/A - Had a little bit of defending to do in his 10-minute cameo. Photo: Naomi Baker
17. Oliver Langford (referee)
8 - Unfussy but used his whistle when he had to. It wasn't a dirty or controversial game to deal with. Photo: George Wood