The 26-year-old added a Peter Brock Trophy to his 2023 championship title, reminding everyone of his brilliance amid a torrid season with Erebus Motorsport.

Kostecki and co-driver Todd Hazelwood entered the event confident they had a fast car, but the build-up to the race was complicated by the West Aussie’s apparent illness.

He qualified fourth fastest on Friday having tagged the wall at the top of the hill during the session, requiring a quick replacement of suspension arms.

Kostecki went on to score pole in the Saturday Shootout and subsequently mentioned that he’d been “feeling a little bit off, there is a bit of a bug going around”.

He spoke further on it via Supercars’ latest Drivers Only Podcast, where he was joined by Hazelwood.

“I had the shits with myself, but I literally had the shits that day,” said Kostecki when asked of his qualifying incident.

“I was feeling horrible. It was not good. I wasn’t feeling good on Friday.

“I was just minimal laps trying to stay fresh for qualifying. I was getting a bit of double vision and all that sort of stuff going on. Bit feverish.

“I was glad to actually just put it in the Shootout, to be honest.”

Hazelwood noted that Kostecki asked at one point if he was “ready to put this thing in the Shootout”, indicating Kostecki was not feeling well enough to even drive in qualifying.

Kostecki reported on Saturday that he was “on the mend”, setting the stage for Sunday’s masterclass.

His only issue in the race appeared to be a loose air hose fitting on his helmet, which mentor Paul Morris was seen fixing with a hot glue gun between stints.

However, Kostecki revealed he had nearly crashed early in the race at the same spot that caught out David Reynolds and Will Davison in qualifying.

“I had a moment actually down the hill in the first stint,” he said.

“I guess someone went a little bit wide or something, put yellow sand on the track. Going down the hill, I almost fenced it.

“It was pretty close, similar to what actually Dave did.

“Broc [Feeney] was right behind me on that. After the race, he come back to me, he goes, ‘holy fuck, I don’t know how you didn’t crash!’”

Kostecki was put under pressure by Feeney over the final stint to the flag following the race’s one and only Safety Car.

“Those last 30 laps there were gruelling, they were so intense,” Kostecki recounted.

“It was within a second for a lot of, you know, for over 50 percent of that last stint. And I’ve got a display on my dash that shows me how far Broc was behind me.

“I’d be going down the hill every lap, pretty much hanging my balls out on the line ready to write this Chiko roll off and roll through the sand.

“I’d get to Forrest’s Elbow and I’m like, ‘surely I’ve put I’ve put a gap on this little prick behind me’, and it’d come out exactly the same.

“And I’d be like, ‘fuck, how much more have I got to do to have a safe buffer?”

Kostecki took the chequered flag 1.3s clear of Feeney. Their fastest laps were both set on lap 142, with the Triple Eight car 0.0153s faster.