A tireless display against the Hornets gave Rovers more breathing space at the wrong end of the Championship.
Jason Euell’s first goal for Doncaster earned the hosts a share of the spoils after Danny Graham had headed the visitors in front midway through the first half.
And Rovers, whose drive and determination appeased the Keepmoat Stadium faithful, were unlucky not to take all three points after piling late pressure on a physical Watford side who saw John Eustace sent off late in the game.
Chairman John Ryan sat next to the South Stand drummer in a bid to galvanise supporters who have seen their injury-hit team slip down the division in recent weeks.
But the home fans were silenced when Andy Weimann headed back Don Cowie’s cross and left Graham with a simple headed finish from two yards out.
Doncaster rolled their sleeves up, however, and Billy Sharp fired just wide before Sam Hird picked out Euell and the on-loan Blackpool striker was given the space and time to rifle Rovers level in first half stoppage time.
Euell raced clear at the start of the second period only to see his first effort blocked by Hornets keeper Scott Loach and follow-up shot deflected away as Doncaster went in search of a first win in six.
When Eustace, who had earlier been carded for a crude challenge on Euell, received a second yellow for handball it handed the initiative to Rovers.
But despite throwing men forward Paul Keegan’s close range volley, which deflected inches wide, was the closest the home side came to finding a winner.
The point was enough to move Rovers eight points clear of the drop zone after the bottom three sides - Preston, Sheffield United and Scunthorpe - all lost.