Both Singleton and White Knights Baldivis collected wins to remain the only undefeated teams on the Peel Cricket Association ladder in round five action over the weekend.
The Irwinians gave a stirring performance with the ball to keep Halls Head at bay, while Baldivis received an unbeaten 84 from David Melia to lead their charge against Waroona.
Electing to bat first, Singleton looked on the ropes when Scott Martin struck to claim back-to-back wickets in Tim Hutchison and Kurt DeAmyand, both going lbw.
But 41 from Daniel Jones before a half century from Bryce Evans (53) helped steer the ship, and saw the home side to 187 despite Martin and Michael Chappell combining for eight wickets on the day.
Halls Head's chase was off to a decent enough start with the top order providing an even spread of runs, but Jay Boyd's bowling spell proved fearsome.
He finished the day going 5/31, leading a group that dismissed the home side for 142, well shy of the total.
The win keeps Singleton unbeaten atop the ladder through five rounds, but the White Knights remain just one point behind after their own impressive victory over Waroona.
Melia was the driving force in that win, as he smashed out 11 boundaries (one six) on his way to 84 not out off just 78 deliveries.
That knock helped set up a final score of 8/214, and although Waroona skipper Ben Wright did his best to top the feat, it wasn't enough to secure a win for his side.
Wright found the boundary 17 times (three for six) as he compiled an unbeaten century with 109 runs to spur his side's chase, but the Warriors ended five runs short after batting out their overs.
In other results, Kane Standing's 54 not out led Warnbro to their second win of the season as they toppled Pinjarra. The reigning premiers are yet to claim a win on the new campaign.
Ian Lattimore's 4/16 bowling figures locked in Mandurah's first victory of 2020/21, with his prosperous spell giving his side all they needed to defend 178 total, largely carved out by Matt Jenkinson's 65 runs.
And South Mandurah tightened their grip on a top-four spot, as Jesse Buck scored 49 runs and Corey Tregenza captured five wickets in a resounding victory over Shoalwater Bay.
The coming weekend's action will be highlighted by what looms as an epic clash between the top-two Singleton and White Knights Baldivis at Stan Twight Reserve on Saturday.