Kostecki controlled the 250km race from pole position to add a Gold Coast victory to his Bathurst 1000 triumph a fortnight ago.

Brown and teammate Broc Feeney rounded out the podium, leaving the gap between the teammates at 180 points heading into next month’s Adelaide season finale.

The Triple Eight duo are now the only two drivers in contention after a refuelling issue for Chaz Mostert left him 11th in the race and 309 points adrift in the standings.

Kostecki had made the most of pole to lead Brown to the first corner, while Mostert held third despite contact from Jack Le Brocq that kicked the WAU Mustang sideways through the chicane.

The real opening lap action, though, unfolded deeper in the top 10 as a touch from Anton De Pasquale on Ryan Wood triggered a multi-car pile-up at Turn 11.

A Safety Car was called to retrieve De Pasquale’s Mustang from the circuit, while Nick Percat and James Courtney’s cars required lengthy garage visits to repair damage from the melee.

The race finally restarted on lap seven with Kostecki leading Brown, Mostert, Le Brocq, Matt Payne, Feeney, Cam Waters, James Golding, Thomas Randle and Richie Stanaway.

PremiAir Racing opted for an early stop with Golding on lap 10 but, for the second day in a row, a bungled wheel change took the Nulon entry out of contention.

Payne was the next of the front-runners in on lap 23, triggering Le Brocq, Randle, Feeney, Mostert, Brown and then Kostecki in on subsequent laps as they each attempted to cover their positions.

Feeney was the winner of that – jumping Le Brocq and Payne to emerge from the cycle behind only Kostecki, Brown and Mostert.

Waters though stayed out until lap 33 – the same lap he’d pitted on during Saturday’s winning run – and rejoined in ninth but with less fuel to take on at his second stop.

The Monster Mustang was the car to watch in the second stint, picking off Reynolds, Le Brocq, Payne and Randle over the next 20 laps to emerge as a podium threat.

Kostecki meanwhile edged away from Brown, who expressed concerns over bent steering and continued to have title rivals Mostert and Feeney for close company.

Feeney kicked off the second round of stops on lap 54, followed in a lap later by Brown and Mostert. Brown emerged just ahead of Feeney, both comfortably clear of the Ford.

Kostecki and Waters were in for service soon after; Kostecki rejoining with a three-second lead over Brown, while Waters slotted in behind the two Red Bull Camaros but ahead of Mostert.

Waters’ attempt to apply pressure to Feeney soon resulted in him tagging the tyres at the first chicane, bruising the left-front corner of the Mustang.

Mostert, though, was in far bigger trouble; forced to pit on lap 64 for another splash of fuel.

It turned out the team had mistakenly used teammate Ryan Wood’s fuel rig at Mostert’s second stop, resulting in only a small splash of fuel being ingested.

The mistake took Mostert out of contention and triggered a post-race investigation.

There were no more late twists at the front as Kostecki controlled the pace to win by 3.4s over Brown, who led Feeney and Waters to the chequered flag.

Randle made it two Tickford Mustangs in the top five, while Le Brocq took the flag sixth but dropped to eighth following the late issuing of a five-second time penalty for an unsafe pit release.

That elevated Andre Heimgartner and Stanaway to sixth and seventh, while Le Brocq, Payne – who lost ground with a slow second pit stop – and Reynolds rounded out the top 10.

Mostert was left to rue another day of missed opportunity in 11th ahead of Mark Winterbottom – who had led laps by running long – and the recovering Golding.

Results: Repco Supercars Championship, Boost Mobile Gold Coast 500