The first of the two Sunday races saw British Touring Car Championship race winner Oliphant score a maiden win on Aussie soil.
The Alfa Romeo driver started the race from pole thanks to the partially-reversed grid.
A strong start then saw him take a lead he would hold until the finish after keeping Audi driver Clay Richards at arm's length across the distance.
Richards, on debut in TCR Australia, had his own hands full throughout the race, initially from Peugeot driver Ben Bargwanna.
Another Peugeot driven by Jordan Cox then went on a late charge, moving past Bargwanna before setting after Richards.
However a spin at turn seven a couple of laps from home sent Cox to the back of the field and left Richards to finish second ahead of Hyundai's Josh Buchan.
Race 1 winner Michael Clemente didn't feature in the second race at all, a clutch issue for his Cupra leaving him stranded in the pits before the start.
The final race of the weekend started with Hyundai pair Bailey Sweeny and Buchan on the front row thanks to their points haul to that point.
Sweeny got the jump on his teammate and was never headed, adding to his series lead with a dominant 20s victory – the second biggest winning margin in series history.
"The championship is on the mind, but a race win is always the goal," said Sweeny. "It feels like we had mega pace all weekend, it was good to put on a show in the final race."
Buchan, meanwhile, came under pressure from Zoutar and a fast-starting Clemente, who made up four spots in the first two laps in is repaired Cupra.
Buchan was able to gap his pursuers slightly as Clemente pressured Soutar, before grabbing third place at turn 7 three laps from home.
Clemente then looked to grab second from Buchan, only to tag the back of the Hyundai at the third-last corner on the final lap.
He then slowed up to redress and let Buchan continue at second, Soutar looking to take advantage and pass them both on the run to the penultimate corner.
However there was contact between Soutar and Celemente, the former able to continue and finish third behind Buchan, while the latter ended up smacking the wall and ending up bogged in the mud.
"I was minding my own business," explained Soutar. "Michael got into the back of Josh, which was probably a bit risky on the last lap when they're both in the championship.
"All of a sudden I came around the corner and they were there. I think Mikey was backing off to let Josh back ahead, Josh looked slow because he had the bumper hanging off, and I just went where I could.
"I tried to go around them, and then I got pushed into the dirt and I tried to come back on. I don't know, that's all I can tell."
Clemente took the blame for the crash.
"Pretty gutted," he said. "I locked it up into the third last corner and hit [Buchan] off. I tried to stop and let him come back on, I didn't want to do anything wrong.
"Once all three of us bunched up I ended up in the wall. It was my own fault."
The late drama promoted Cox to fourth ahead of Lachlan Mineeff (Audi) and Tony D'Alberto (Honda).
Sweeny now holds a 36-point series lead over Buchan at the mid-point of the season.
The 2023 TCR Australia season continues at Queensland Raceway on August 11-13.
