But Shrewsbury's victory, just their third of the season, owed much to an outstanding display from goalkeeper Chris Weale. The former Leicester man produced some stunning saves inside the opening 15 minutes, the pick of them when he tipped a Florent Cuvelier shot round a post.
Weale also made fine stops to deny both Jamie Paterson and Adam Chambers as the Saddlers came flying out of the blocks.
Shrewsbury had carried no threat until they broke the deadlock totally against the run of play in the 25th minute. Walsall were unable to clear a corner and when Asa Hall's shot came back off the bar, former Wales international Parry reacted quickest to stab in the rebound.
Walsall continued to pepper the Shrewsbury goal in the second half, Andy Butler heading against the crossbar, while Weale pulled off another fine stop from George Bowerman.
Shrewsbury might have doubled their lead when Marvin Morgan set up Parry only for his 15-yard shot to come back off the bar.