Feeney made a good getaway from pole, initially leading the race from fellow front-row starter Lostecki.
The series leader only last three laps in second place, though, until teammate Brown eased past at the last corner.
The trio ran in that order until lap 20 when Kostecki was first to hit the lane.
He re-emerged behind an early stopping Tim Slade, who had taken his service from fifth place on lap 11.
Brown waited until lap 24 to take his stop, he too coming back out behind Slade.
The Erebus Camaros were able to clear Slade by lap 29, at which point Feeney came in for his stop.
The squabble behind helped to him have enough gap to come out with his lead intact and a 2.5-second margin over the two Erebus entries.
That was all the second-year driver needed to set up a third Supercars victory, his final winning margin over Brown and Kostecki 6.8s.
"I didn't know what it was going to be like today; these [Erebus] cars have been so fast and we've struggled in the pack this weekend," said Feeney.
"Once I got the start, the first five laps I thought we had a pretty good car. This thing was so good to drive in that race, I had so much fun. I could just manage the tyres as best as I could and at the end let loose with some speed. Bloody awesome."
Third place helped Kostecki retain his series lead, the margin over Mostert 100 points.
Reynolds ended up fourth for the race in his Grove Mustang, having followed the Erebus cars past a struggling Slade early in the second stint.
Chaz Mostert also got through Slade, as did Cam Waters and Will Davison.
The battle for ninth went right down to the wire, Courtney holding on under extreme pressure from Scott Pye, James Golding and a recovering Shane van Gisbergen.
The Kiwi had come from 21st on the grid and copped a lengthy stop for four fresh tyres, before using his grip to make a net gain of nine spots.
The 2023 Supercars season continues in Tasmania midway through next month.
