Mostert surprised by P2 after qualifying setback

Before Friday night's first Sydney race, Chaz Mostert had few hopes of a podium finish from eighth on the grid.

By night's end, he was second.

Mostert charged from the fourth row to second by the flag, albeit nearly 17 seconds behind runaway winner, Tickford Racing rival Cam Waters.

The Walkinshaw Andretti United driver climbed over Penrite Racing driver Matt Payne in the closing laps, before Payne was passed by Waters' teammate Thomas Randle on the final lap.

Mostert jumped from eighth to fifth on the opening lap, and after passing Randle, was in contention for a podium after Broc Feeney suffered a shock tyre puncture.

With three laps to go, Mostert put his strategy to use, passing Payne for second. Where Payne had taken on two tyres early, Mostert took on four, and went on to claim a first-up podium.

"Didn't expect it, that's for sure," the 32-year-old said after the race.

"Even in the race, we didn't quite have the best balance today.

"We stuck to our strategy, we ran a bit longer to have some more tyres, but I didn't really think those last couple of laps... I thought it was going to equal out with Matty Payne there.

"He probably is the man of the match today, obviously he missed out on a trophy, but yet again those guys showed, that two tyres, they still had some amazing car speed.

"Lucky we stuck to our guns with strategy today."

Mostert had it all to do from eighth after struggling with one-lap pace. The two-time Bathurst winner had to do a second push lap to even get to eighth in Q2.

"We chased our tail trying to be aggressive," he said.

"I was pretty lucky in the eight-minute Part 2, because if it was [a Shootout], I would've been 10th. I had to trundle around and go for a second lap."