Rovers’ last draw had come on February 28 – one of six successive draws at the time – and they had gone 34 league games without another one until this deadlock.
Burnley loan striker Daniel Agyei almost put Walsall ahead after 20 minutes, beating two defenders on a fine solo run into the box but his shot was clawed away by Rovers keeper Adam Smith.
That was the only chance of a poor first half but the game improved after the break.
Rovers had a golden chance after 52 minutes as Tom Nichols latched on to Liam Sercombe’s flighted ball but his prod towards goal was foiled by sprawling Walsall keeper Mark Gillespie.
Walsall then got on top as Zeli Ismail fizzed a cross-shot just wide before Smith made a superb diving save to push aside Joe Edwards’ 20-yard drive.
Rovers came on strong late on but when Rory Gaffney’s speculative 35-yarder flashed just wide, they had to settle for a rare draw.
Watford boss Javi Gracia does not think Abdoulaye Doucoure's form will be affected by his omission from France's latest squad.