Fleetwood Town handed League Two leaders Walsall their second consecutive loss with two headed goals in the first half.
The Cod Army, coming off a loss to second-bottom Carlisle at home over the weekend, took the lead after just 10 minutes thanks to a goal by defender Shaun Rooney.
Rooney, a former St Mirren player, scored his second goal in a week after a well-placed curling free-kick from full-back Mackenzie Hunt.
Shortly after, Hunt's corner kick led to Town doubling their lead in the 17th minute with a header from center-back James Bolton.
Walsall, without their captain Jamille Matt, struggled to mount a significant offense in the first half, with Jamie Jellis' weak attempt being their only notable chance.
In the second half, Hunt continued to create chances with his crosses into the Walsall box, with Bolton coming close to scoring again around the hour mark.
Fleetwood Town managed the game effectively and became the first team this season to beat Walsall twice in league matches.