The visitors started brightly and took the lead in the 12th minute when Cristian Battocchio threaded a pass through to Lewis McGugan, who fired a shot at goal, and although it was blocked, it fell into the path Troy Deeney, who found the net from close range.
Watford came close to doubling their lead as McGugan almost turned provider again as he slipped a through-ball into the feet of Ikechi Anya and he drove an effort at goal from distance that went inches wide of the post.
Gianfranco Zola's side doubled their lead just before the break. They raided forward on a counter-attack and Hector Bellerin slid a through-ball for Battocchio, who found the net from close range by beating Paddy Kenny.
After the break, Leeds began their fightback as Matt Smith knocked the ball out wide on the left to Danny Pugh, who took a touch past Nyron Nosworthy and found the corner of the net with a low effort.
Brian McDermott's side were soon level following another good move. Ross McCormack raided forward and lifted a cross into the area and Smith managed to get on the end of it to head an effort past Jonathan Bond.
Leeds took the lead in the 78th minute when Luke Murphy launched a ball forward for McCormack to chase and he controlled the ball before advancing into the box and slotting an effort past Bond.
The game was not over, though, as Watford hit back. Deeney turned the ball home from close range pouncing on a rebound after Kenny had failed to hold an effort from distance from George Thorne to secure a point for Zola's side.