A second half storm helped the Mandurah Mustangs conjure their first win of the 2019 campaign when they buried the Demons 13.14 (92) to 6.7 (43) at Rushton Park on Sunday.
Four goals from Alex McLeod and a prolific performance from Alex Cohen spurred the side on after a sluggish second quarter allowed Waroona back into the game.
Mandurah started with the hot hand, booting three goals to the Demons' one through the boots of McLeod, Cohen and Blayne Hull to take a 12-point lead into the first break.
But the Demons, thanks to influential outings from Bailey Taylor and Rowan Gardiner, clawed their way back into the contest to trail by just five points at the long break.
Waroona had momentum at the half, but it didn't last as Mandurah landed blow after blow in the final two quarters.
Inspired by solid games to Brandon Penny and Jackson Burkett, the Mustangs piled on four goals to Waroona's one in the third term with McLeod and Sam Evans among the scorers.
From there Mandurah seized total control with both Cohen and McLeod nailing a pair of majors to finish the game off strong before Jayden Dowling capped off a memorable win for the red and white.
Gardiner, Zac Moody and Jack Strand all finished with two goals for the Demons, accounting for six of their total seven majors.
Mustangs coach George Costello labelled the win an inspiring one for his young side, while praising the hard work of McLeod, who finished the day with four goals, four behinds.
"The boys were probably a little panicky at half time. Waroona came back in the second and gave us a real hard go," he said.
"To see them not drop their heads and fight out what was a big win in the end, that's a really big step forward for our group.
"We've got a bit of a new belief in a sense, so it's important for us to get some reward for effort and see the results of the hard work all the boys are putting in.
"I thought [McLeod] was a real force up forward. That sort of performance is what you ask from your key forwards and goal-kickers so we're rapt to see him slotting in well."
The Mustangs have now won three games since the start of the 2018 season, all against Waroona.
But they'll be looking to buck a trend rather than keep one rolling when they face off against South Mandurah on Anzac Day, who they haven't beaten in several years.
"Before the year started we penciled in a few games that we thought would be quite big for our club, and this is one of them," Costello said.
"If we can come away with a win on Anzac Day it's going to do wonders for our group's morale."
Meanwhile Waroona will enjoy the bye week before they host an undefeated Pinjarra outfit.