Wanganui driver Earl Bamber snatched victory with a late move that thwarted fellow teenager Mitch Evans' bid to be the youngest winner of the New Zealand Grand Prix (NZGP) at Manawatu's Manfeild circuit.

But Evans, 15, from Auckland still had reason to smile because he heads away from the penultimate round of the Toyota Racing Series having won the international component of the competition and leading the the national series.

The rookie had looked good to win the NZGP, the biggest prize in national domestic motorsport, having dominated the 12-car field from the start of the 35-lap feature.

But a safety car intervention with five laps to go proved a game-changer.

Soon after the restart, Bamber nipped ahead of Evans and maintained the lead until the flag.

Bamber, 21, a former A1GP racer, hadn't imagined the win would be his.

"I was hunting him (Evans) down but the race was close to ending - I didn't think we'd get it."