Thomas Randle was delighted with a "really cool" run to fourth in Albert Park qualifying.
Randle was a big surprise story from Friday’s second qualifying session.
The Tickford Racing driver qualified fourth for Race 9, which will be held on Sunday.
Shell V-Power Racing Team veteran Will Davison clinched ARMOR ALL Pole Position for the race.
Randle recorded his best effort in the final moments of the 12-minute session, and demoted Shane van Gisbergen to sixth.
It marked a jump on his previous best qualifying of ninth, which he achieved on Thursday.
It comes after two-time Formula 1 champion Fernando Alonso sampled Randle's Tickford Mustang at Albert Park on Thursday.
"I just managed to put it together to do my job right," Randle told Supercars.com.
"Because we were on the hard tyres today, I probably didn't know what to expect.
"I'm still quite new to running on different compounds.
"After the first qualifying session today, I thought we still needed to tune the car a little bit.
"After we did that, I thought I could do a bit better job.
"Then I went down and straight, recorded my time, and looked on the leader board from 10th to a fifth.
"I thought, 'I'm not even on there, geez, what does it take to get in the top 10?'
"Then my engineer said I was fourth. So, it’s really, really cool."
Randle, who turned 26 on Thursday, will share the second row of the grid with Chaz Mostert.
Randle with Alonso on Thursday
The top three of Davison, Anton De Pasquale and Mostert were covered by just 0.015s.
Tickford teammate Cam Waters will line up fifth, with James Courtney launching from 10th.
Randle, who is 22nd in the championship standings, praised his team for the set-up of his car.
"The car was fantastic. Thanks to the whole team at Tickford and all my supporters," he said.
"It’s the first time here in a Supercar for me, I had a PB qualifying yesterday with ninth, and then just sprayed it in qualy two.
"I really wanted to repay the boys today.
"We just got it all hooked up for the last one, so very much looking forward to the last race on Sunday."
Cars will take to Albert Park for Race 6 at 2:20pm AEST.