Latics and Saddlers share points
Saddlers substitute George Bowerman struck 11 minutes from time to cancel out a first goal in English football from Oldham's French midfielder Youssouf M'changama.
Jordan Slew drilled an early shot wide from the edge of the box for the Latics, while Walsall goalkeeper David Grof did well to beat out Robbie Simpson's long-range free-kick.
The Saddlers came to life with two chances for Will Grigg, but Oldham made the breakthrough after 36 minutes when M'changama let fly from 25 yards and Grof was at fault as the shot went through his dive.
Oldham keeper Alex Cisak also made a mistake just after the break when he allowed Jamie Paterson's set-piece to squirm through his hands, only for the ball to drop inches wide.
Walsall were gifted the equaliser after 79 minutes as home captain Dean Furman hit a weak backpass and Bowerman intercepted before slotting beyond Cisak from inside the area. The visitors could have won it late on but Paterson's angled shot flew off target.