Phillip Island S5000: Mawson wins crash-affected finale

There was drama from the moment the lights went out, a fast-starting Nathan Herne clipping the rear of pole-sitter Thomas Randle's car.

That sent Herne skywards, a rough landing leaving him in need of on-site medical attention.

The race was red-flagged while Herne was extracted from the car by the medical crew, the teenager eventually walking to the ambulance under his own steam allying fears of serious injury.

A rolling start got things going for a second time in what became a time certain race, Randle initially leading the field, bit unable to shake Team BRM teammate Mawson.

A lock-up for Randle at Southern Loop on Lap 7 then opened the door for Mawson to sneak up the inside and grab the lead, while the former leader was dumped back to fourth behind Tim Macrow and James Golding.

From there Mawson sprinted to a second S5000 race of the season.

"I didn't expect to win this race, I was hoping for a podium back from where I was starting," said Mawson. "After the set back in qualifying to end up with a victory, I didn't expect it. I'm overwhelmed and really happy for the team."

Macrow and Golding continued to scrap over second place in a battle was only decided on the final lap when Golding barged his way through to relegate Macrow to the bottom step of the podium.

Randle finished fourth after holding off impressive rookie Kaleb Ngatoa, who had never driven an S5000 before this weekend.

But the young Kiwi's charge was undone on the final lap when he ran wide trying to pass Randle and dropped back to eighth behind Luis Leeds, Cooper Webster and Ricky Capo.