The #1 Erebus Camaro was the sixth car on track and Kostecki put in a typically high-commitment lap to stop the clocks at 1:10.3150s – eclipsing Will Brown’s benchmark by 0.2836s.
Rookie Ryan Wood was next out and did not record a time due to a kerb strike, before Broc Feeney, Cam Waters and Matt Payne all failed to get within half-a-second of Kostecki.
Those final laps took place after early cloud cover gave way to beaming sunshine, appearing to impact track grip.
Kostecki and Brown will share the front-row ahead of Jack Le Brocq, Chaz Mostert, Feeney, Payne, Waters, Richie Stanaway, James Golding and Wood.
The result was redemption for Kostecki after he ended Saturday’s Shootout at the bottom of the order due to a kerb infringement.
“I’m glad I got this today, it makes up for yesterday,” said Kostecki.
“The car was really good in the race yesterday, we tuned it up a bit for today and it was a rocketship then. A big thanks to the whole crew, it’s been a great few weeks.”
It marked Kostecki’s second pole position in two weeks after scoring his first of the season at the Bathurst 1000.
The $6,500 pole award was presented to Kostecki by Boost Mobile founder Peter Adderton.
On this occasion not only did the driver don a Boost Mobile cap, but the entire Erebus Motorsport crew did also in a surprise twist to the hot and cold relationship between the sponsor and team.
Erebus was earlier in the weekend fined $5000 for failing to open its garage doors for a Boost Mobile Gold Coast 500 pit lane party.