Tom Bradshaw missed several chances for the visitors early on, including an effort which hit the home crossbar.
However, Bradshaw gave the promotion hopefuls the lead with a penalty following a George Cooper handball.
Crewe drew level when Brad Inman nodded in after Semi Ajayi headed on David Fox's free-kick and the home side held on for a point.
Walsall head coach Sean O'Driscoll told BBC WM:
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"I'm just really pleased with the level of performance once again. We could've been out of sight in the first 10 minutes, but that's a different Crewe side to what you usually see.
"Defensively, we were excellent. Yes I'm disappointed in the result, in the sense that we did enough to warrant getting more than a point."
Crewe extended their unbeaten run to five matches as the relegation battlers held Walsall to a draw.