Brodie Kostecki has shrugged off a handling issue to deny Thomas Randle in Sunday’s first race at the OTR SuperSprint.
The championship leader, who won Saturday’s sprint from pole, took the lead from first-time pole-sitter Randle in the opening corners and was never headed.
Kostecki reported a steering problem in his #99 Coca-Cola Camaro in the closing laps, but managed to issue to take his fifth victory of the season.
The end margin between the Erebus Motorsport Chevrolet and the #55 Castrol Mustang was 1.0687s, with Chaz Mostert overhauling David Reynolds for third on the final lap.
Kostecki took home all 105 points on offer with the fastest lap set on lap 3, and extending his championship lead over Shane van Gisbergen.
Van Gisbergen held off Penrite Racing rookie Matt Payne to finish fifth, with Anton De Pasquale, Bryce Fullwood, Broc Feeney and Andre Heimgartner rounding out the top 10.
Will Brown, who was second in the points heading into the event, drifted further from teammate Kostecki in the standings after finishing 13th.
Kostecki will carry an 111-point lead over van Gisbergen into Race 22, with Feeney 148 points down. Brown is 202 points behind, with Mostert 67 points behind the #9 Erebus Camaro.
Erebus, meanwhile, eked its teams' championship lead over Triple Eight out from 43 to 62 points.
"It felt really strange, I couldn't brake in a straight line, the car was wandering our a fair bit," Kostecki said.
"It was pretty scary the last sort of 10 laps there, we were sort of happy to had enough car speed to stay in front of Tom.
"It was a really tight drag race down to Turn 1, it was pretty lucky to stick around around the outside there, he raced me pretty clean."
Randle and Kostecki dragged down to Turn 1 as lights went out, and the championship leader rounded up the Castrol Ford around Turn 2.
Four corners later, the key flashpoint of the race unfolded as Jack Le Brocq went deep into Turn 6, and sent Cam Waters and Will Davison into a spin. Le Brocq was later handed a drive-through penalty over the incident.
Waters and Le Brocq were forced into the lane with toe link and panel damage, with the passenger door also coming loose on Davison’s Shell V-Power Ford.
Percat, Fullwood and Jones were first to stop on lap 5, Reynolds and Slade on the following lap, and De Pasquale and Courtney on lap 7.
Randle stopped from second on lap 8, with Brown — who vaulted from 16th into the 10 — following the Castrol Ford in. Erebus responded and pitted Kostecki on the following lap, with Payne also pitting.
Van Gisbergen carried on until lap 10 and emerged behind Kostecki, Randle and Reynolds, with Payne, Mostert and De Pasquale behind.
Kostecki reported a steering issue in the closing laps as Randle kept a watching brief, with Reynolds keeping van Gisbergen at bay. Behind them, Mostert picked off Payne for fifth on lap 15.
Van Gisbergen and Mostert took off after Reynolds, who was ailing after his early stop. Van Gisbergen launched an attack at Turn 3, but suffered major locking into Turn 6. Mostert needed no invitation, and went through after Reynolds.
Mostert had one opportunity on Reynolds and took it at Turn 1 on the final lap, and set sail on his fourth podium in six starts. Behind them, van Gisbergen was forced to defend from a racy Payne.
Waters and Le Brocq were classified 24th and 25th, with Davison 22nd. James Golding, who also picked up damage in the first-lap incident, was classified 23rd.
The OTR SuperSprint will conclude with Race 22, also at 20 laps, at 3:50pm local time/4:20pm AEST.