Watford were on course to leapfrog Hull City into second place until an stoppage-time goal from Burnley's Sam Vokes halted the home side to a 3-3 draw at Vicarage Road.
An eventful first half resulted in both teams snatching two goals apiece, with Charlie Austin netting the opening goal for Burnley from six yards out.
Watford replied with an equaliser from Troy Deeney, who hammered the ball into the bottom-right corner of the net with a 25-yard shot, but the 1-1 scoreline was short-lived as Austin doubled his goal tally with a penalty.
The home side were able to draw level before the break through Fernando Forestieri, who slid the ball into the back of the net after picking it up from Fitz Hall.
It was a tentative start from both sides in the second half until Watford almost took the lead through Hall, who met the ball with his head from an Almen Abdi corner.
Hall launched his header from close range but the ball drifted wide of the left-hand post to go out for a goal kick.
At the other end, Alex Kacaniklic had a chance to regain the lead for Burnley, but his shot was saved by Jonathan Bond to keep the game level around the 60-minute mark.
While Lee Grant was able to keep Deeney's header out, he was unable to stop Forestieri firing into the far corner after latching onto Deeney's mis-kick to put Watford 3-2 ahead.
The home side's hopes of reaching second place were quashed during the five minutes of added time when Vokes stole the ball from the home defence and drove his effort into the bottom corner of the net.