Honours were even between front row starters Brown and David Reynolds when the lights went out, Brown retaining the lead on the way out of Turn 1 thanks to having the inside line.
Reynolds initially dropped into second, however left the door open for a lunging Brodie Kostecki to sneak through at Turn 7 on the first lap.
A lap later Reynolds was too timid in his defence again as Anton De Pasquale tried the same move into Turn 7 to grab third. The Shell Ford driver executed poorly, though, bumping Reynolds wide.
The contact dropped De Pasquale to seventh and Reynolds to 12th, with the former also copping a 15-second penalty from race control for his efforts.
Out front the Erebus cars continued to run 1-2, while James Courtney found himself running third.
The lead pack held station across the first stint, Kostecki the first to take his mandatory service on lap 20. Courtney came in three laps later while Erebus left Brown out until lap 26.
The undercut proved powerless, though, Brown resuming with a two-second margin over Kostecki.
From there was no stopping the Coca-Cola Camaros, Brown charging to a second career victory ahead of Kostecki with 6.2s splitting them at the finish.
"I got off the start alright, Dave got a good one but I was able to get him into [turn] 1," said Brown. "And then I don't know, I had a bloody fast car. I kept going. I was wondering if I was pushing too hard and not conserving but it was really fast."
Courtney came home in a lonely third, well behind the Erebus cars but solidly ahead of fourth-placed Chaz Mostert.
The battle for fifth was robust, though, with Will Davison trying to hold off Shane van Gisbergen in the closing stages. The Kiwi eventually got the job done, passing Davison at Turn 7 on the penultimate lap.
Todd Hazelwood kept his solid weekend going with seventh ahead of Cam Waters, Matt Payne and Andre Heimgartner.
The Perth SuperSprint comes to a close with a third race at 3:45pm local time.
Supercars Perth - Race 2 results
Results to follow