Brodie Kostecki romped to victory in the 250km race to finish 3.470s clear of Brown, while Feeney and Ford flyer Cam Waters followed closely behind in third and fourth.
Curiously, timing showed Brown lose half-a-second to Kostecki – and also his own previous lap time – in the first sector on the final tour, allowing both Feeney and Waters to close in.
Feeney said post-race that he’d by that point given up on passing his teammate and just wanted to keep the charging Waters at bay.
“I think when [Brown] came out of the pits, he was obviously quite fast, so it was just sort of follow the lead up for most of that,” Feeney said of the situation throughout the final stint.
“I was probably a little bit quicker through the first couple of corners than Will but then he was quicker for the rest of the lap.
“On the last lap, I think he made a mistake and locked the front and bowled a wide.
“But I think at that point I was more worried about Cam behind me, so I was on the radio just saying, ‘hurry up and go, like, I’m not going to pass here. Just get a move on’.”
Brown had suffered from steering problems midway through the race, reporting an inconsistent feel from the rack.
“We had some major steering dramas there where it was just going left-hand down, really struggled with that throughout the race,” he said.
“It came on about lap 40, it was like the steering was changing… it was a little bit nerve-racking through the chicanes trying to keep it off the walls.
“It actually came in and out, so it got better halfway through and then I started going again, so that was good.”
The Sunday result leaves Brown with a healthy 180-point advantage over Feeney heading to next month’s Adelaide 500 finale, with the Triple Eight drivers now the only two in contention.