WA Rugby League premier grade leaders South Perth Lions swept aside their nearest challengers North Beach Sea Eagles 32-6 on Saturday.
The Lions took a 4-0 lead before the visitors scored their only try of the game.
The Sea Eagles spent plenty of time in the opposition half but failed to capitalise and the game ended with Sky Wanahi and Jon Phipps both sent to the bin.
Joondalup Giants maintained their spot in the top four with a scrappy 16-14 win against the Fremantle Roosters.
The Roosters were denied a try in the dying stages but it would have robbed the Giants of a deserved victory.
Kicking was the cornerstone of the Giants' victory, with countless high bombs tormenting the Roosters defence.
They went out to a 14-4 lead midway through the first half, the Roosters worked their way back into the contest but poor ball handling let them down.
In the final game of the round Willagee Bears held off a strong finishing Kalamunda Bulldogs to run out 22-14 winners.
The visitors went into the break 18 points clear but the Bulldogs stormed back to within four before a final try 10 minutes from time sealed the win.