Roy Hodgson's second-bottom hosts have lost their last eight home games but fifth-bottom Leeds are only marginal favourites to take all three points at a best-priced 13-8.
The Hornets are no bigger than 19-10 whilst the draw is on offer at 13-5.
With Whites no 9 Patrick Bamford out injured, Watford's Nigerian international striker Dennis fractionally heads the first scorer market at 13-2.
Joshua King (71-10), Cucho Hernandez (15-2), Ismaila Sarr (15-2) and Samuel Kalu (9s) are rated the other main Watford threats with Rodrigo (15-2), Dan James (17-2) and Sam Greenwood (9s) seen as the other leading attacking lights for Leeds.
For the Whites, bigger odds are on offer about Jack Harrison (12s), Stuart McKinstry (14s) or Crysencio Sumervlle (14s) scoring first and Mateusz Klich is a particularly big price at 28s.
But in a tight market, the bookies have a 1-1 draw priced up as the most likely outcome at 33-5, closely followed by a goalless draw at 27-2.
Leeds are 10-1 to leave with a 2-1 victory but the Hornets are only fractionally bigger at 21-2 to win by the same score.