The Porsche Carrera Cup Australia Championship race winner started seventh, as the grid positions for the top eight finishers were reversed.
After he ended up in the grass on the exit of Turn 1 early in the race, Hedge put together a calculated drive in tricky conditions to claim victory, having to manage a drying track that turned wet later in the race.
“I had my work cut out for me but when the track started to dry I knew that was my moment to push and that was also when I was faster than the other cars so it was either a win it or bin it moment to be honest,” Hedge said.
“I came around the outside and I did get run off into the weeds which was fine but I did then decide to get a bit more aggressive and get the move done.
“It was definitely a difficult race – at the start I was on the radio saying we might need slicks and in the first half of the race we did need slicks but then in the second half of the race we needed wets.
“It was up and down but I'm stoked for the team.”
American Jacob Abel was sixth, ahead of Kiwi James Penrose, with Brit Josh Mason in eighth.
Chloe Chambers and Lucas Fecury rounded out the top 10.
Kiwi Bree Morris finished ahead of Australian Tom McLennan who was the last of the finishers, with David Morales retiring from the race after his left rear suspension broke as a result of being turned at the final corner on Lap 1.
Race 2 Result
1. Callum Hedge (NZ)
2. Ryan Shehan (USA)
3. Ryder Quinn (Aus)
4. Charlie Wurz (Austria)
5. Liam Sceats (NZ)
6. Jacob Abel (USA)
7. James Penrose (NZ)
8. Josh Mason (UK)
9. Chloe Chambers (USA)
10. Lucas Fecury (Bra)
11. Bree Morris (NZ)
12. Tom McLennan (Aus)
DNF David Morales (USA)