Mark Wright's late goal earned Walsall their first win in ten outings - but their celebrations were almost dashed by a harsh penalty award which provided Swindon with a life-saving equaliser seven minutes from time.
Walsall were cruising towards a first win since mid-February through loan man Julian Joachim, who fired the Midlanders ahead with a stunning near-post strike two minutes before half time.
But with Swindon struggling to make any real impact, referee Alan Woolmer penalised Walsall defender Anthony Gerrard for handball during a frantic goalmouth melee.
Gerrard appeared to block a fierce close-range effort from Swindon substitute Andy Caton and Sam Parkin drove home his 22nd goal of the season from the spot.
But Walsall, defending effectively and with Andrew Surman's midfield prompting looking increasingly dangerous on the break, grabbed the winner two minutes from time.
Joachim was at the hub of the action, drawing Swindon goalkeeper Rhys Evans before rolling a short pass for Wright to crack home the winner.