Mawson started from pole thanks to his Race 1 win on Friday followed by a ninth in a crash-affected reversed grid race yesterday.
And he was unstoppable from the front, winning the start and leading all nine laps as he took a dominant six second victory.
That also helped into the lead of Gold Star after three rounds.
Nathan Herne finished second after jumping Garry Rogers Motorsport teammate Aaron Cameron at the start.
Herne did face pressure from Tim Macrow, who also jumped Cameron at the start, but was able to stabilise the gap late in the race to seal second spot.
Cameron came home fourth, about a second back, while regular front-runner James Golding wasn't far behind in fifth.
Blake Purdie was sixth, Cooper Webster seventh as Zane Goddard, Ben Bargwanna and Kaleb Ngatoa rounded out the Top 10.
The Australian Drivers' Championship season continues at Sydney Motorsport Park on May 27-29.
