Kostecki charged from fourth on the grid, bouncing back from a qualifying crash to beat Walkinshaw Andretti United’s Chaz Mostert to the $50,000 prize.

The race was red-flagged with 10 laps to go after conditions worsened and Tickford Racing’s Thomas Randle crashed his #55 Ford Mustang at the infamous Turn 8.

Mostert was the top Finals Series contender while Triple Eight Race Engineering’s Broc Feeney dropped from pole position to fourth behind the other Walkinshaw Andretti United car of Ryan Wood.

Kai Allen was sixth for Grove Racing while Will Brown recovered from a Lap 1 spin off the nose of Randle’s Mustang to finish 10th.

It was a subdued conclusion to the race, with the cars parked in the pit lane when the race was called with less than 10 minutes left on the clock.

“I actually almost stalled it, so just made a bit of a boo-boo,” said Kostecki.

“But I knew George [Commins] had given me a pretty good car and I could pick them off one by one.

“Obviously those two front guys are racing for a championship, so I didn’t want to do anything too silly.

“But I knew the car had the pace and I’m just really happy to pull this off.”

Supercars points after Adelaide Grand Final Race 1

Although he came up short of the cash prize, Mostert was happy to see the chequered flag.

“I’m pretty stoked. Glad to stay on the black stuff,” he said.

“Brodie was super quick there, especially at the start. Then I found my rhythm a little bit, but I’d lost the track position.

“It was cut-throat. The track when it rains out there and you don’t get it swept, the water just kind of sits on top and you aquaplane a bit.

“Me and Brodie on the out-lap after the pit stop nearly stoved it in at [Turn] 4. It was quite slippery.”

THE GRAND FINAL IS ON AND WOW WHAT AN OPENING LAP 😱#RepcoSC #Supercars pic.twitter.com/LMDBZ4QoUq

— Supercars (@supercars) November 28, 2025

Mostert looked to have gotten the jump on Feeney – and they went side-by-side into the Senna Chicane.

Mostert short-cut the second turn, and Feeney shouldered him out of the way entering Turn 3. They were closely trailed by Cameron Waters and Brodie Kostecki, who looked to make early headway.

Into Turn 9, Mostert dove to Feeney’s inside, but ran too deep and relinquished the position on corner exit courtesy of a criss-cross from the #88 Camaro.

Moments later, Brown found himself facing the wrong way at Turn 9 thanks to a hit from Thomas Randle. That dumped Brown from 12th to 25th.

For the incident, the #55 Tickford Mustang was given a 15-second penalty.

The first lap ended with more chaos as James Golding did a 360-degree spin in his #31 PremiAir Camaro approaching Turn 14 after contact with Cameron Hill’s #4 MSR Camaro.

On Lap 2, Kostecki began his charge with a pass at Turn 5 on Waters. Then on Lap 3, Feeney gifted the lead to Mostert and second place to Kostecki when he locked up and ran deep into Turn 4.

FEENEY GOES LONG AND KOSTECKI POUNCES 🤯#RepcoSC #Supercars pic.twitter.com/Px77qmQjwb

— Supercars (@supercars) November 28, 2025

Waters, meanwhile, fell back into the clutches of the battle pack for fifth. Ryan Wood made quick work of the #6 Tickford Mustang.

Waters faded and was soon in the wars with Cooper Murray, who spun off the nose of the #6 Tickford Mustang on Lap 4. The #99 Erebus Camaro suffered damage to the nose after contact with the wall.

Despite his earlier spin, Brown made a remarkable recovery to 12th. Just as the track began to dry, the weather quickly turned and rain began to pummel the circuit with 15 laps to go.

Macaulay Jones threatened to bring out the Safety Car when he grazed the wall at Turn 8.

Randle made sure the Safety Car was called when he ploughed into the barrier, shifting it back half a metre when he aquaplaned.

Randle aquaplanes into the wall at Turn 8 💥#RepcoSC #Supercars pic.twitter.com/xlq8cZ5fFw

— Supercars (@supercars) November 28, 2025

Damage to the left front corner meant he couldn’t continue, and parked in the Turn 9 run-off.

At the time of the Safety Car intervention, Kostecki led Mostert, Wood, Feeney, Waters, Allen, Payne, Andre Heimgartner, Brown, and Anton De Pasquale.

That was the way the order stayed when the cars pulled into the pit lane under the red flag and the race was eventually called.

Results: Repco Supercars Championship BP Adelaide Grand Final, Race 1