It was Yeovil's fourth game without a win since parting company with former manager Russell Slade as the Saddlers came close to taking the lead in the 36th minute but Troy Deeney's goal was disallowed for offside.
Luke Rodgers' speculative overhead kick and Andy Welsh's tame effort were as much as Yeovil mustered in a poor first-half showing.
And seven minutes into the second half Walsall broke the deadlock - Deeney bagging his eighth goal of the season from Anthony Gerrard's flick-on.
The Saddlers lost key defender Gerrard with an injury midway through the second half forcing veteran striker Michael Ricketts to go into the back-four.
But the points were made safe in the 76th minute when Sofiene Zaaboub delivered a perfect cross for Alex Nicholls to steam in and head his sixth of the season.