The Saddlers, who have been struggling in recent times, seldom gave Leeds time to show the sort of football that had brought them victory in their previous three matches.
The pattern was set as early as the seventh minute when Troy Deeney headed Walsall in front from a superb cross by winger Sofiene Zaaboub.
From that point onwards the Saddlers dominated, with Leeds' striking partnership of Jermaine Beckford and Lee Trundle seldom having a look in.
By contrast Walsall's frontmen Deeney and Jabo Ibehre were always threatening, with the former shooting only just over from a 24th-minute cross by Alex Nicholls.
Andy Robinson was easily Leeds' best player. The industrious wide-man had a shot deflected in the 27th minute and Bradley Johnson did have the ball in the net for the visitors two minutes later, but was ruled offside.
Leeds were a little livelier in the second half, playing far more football and passing rather than long balls down the middle which had been their main method of attack in the first period.
It almost paid dividends in the 59th minute when a good move finished with Trundle feeding the ball to Jonathon Douglas who shot hard and low, but Walsall keeper Clayton Ince was in position to save.
Towards the end Leeds began to get into the game more, but substitute Luciano Becchio headed over Robinson 77th-minute cross.
Walsall were still dangerous and in the 86th minute Deeney chested the ball narrowly wide from Anthony Gerrard's free-kick.
As the game entered stoppage time another cross by the outstanding Robinson was again headed over by Becchio as Walsall held on to clinch the three points.