New Zealand's Laurence Pithie powered home to nudge out Eritrea's Natnael Tesfatsion in a sprint finish to claim his first WorldTour victory in the Cadel Evans Great Ocean Road Race in Geelong on Sunday.

The Groupama-FDI rider lunged at the finish line to pip Tesfatsion (Lidl-Trek) by a half-wheel in the tightest finish in the eighth running of the 176-kilometre race along the southern coastline of Australia's Victoria state.

Germany's Georg Zimmermann (Intermarche-Wanty) was third just ahead of New Zealand's Corbin Strong (Israel-Premier Tech) and Ecuador's Jhonatan Narvaez (Ineos-Grenadiers).

They covered the journey in four hours 17 minutes and 40 seconds.

Pithie had to wait for the photo-finish confirmation before he could celebrate his first WorldTour victory with his team-mates.

"Oh, that's incredible," Pithie said. "I had really good positions on the climbs and followed everyone."

The 21-year-old New Zealander surged to the front from a 12-man group which had broken away on the final ascent of the steep Challambra Crescent section of the road race.

Although he was boxed in the final scramble, Pithie was able to move away from Strong's wheel, and come around Tesfatsion to claim victory with a throw to the line.

"I got stuck about one kilometre from the finish," Pithie said. "I knew I had to be patient. We spoke in the briefing this morning, patience was going to be key.

"It was just going at full gas. I was coming back at him (Tesfatsion), I had to close the gap.

"The Intermarche rider (Zimmermann) on the outside, he was coming quick, but I just managed to hold on in the lunge."

American Quinn Simmons (Lidl-Trek) broke away with under three kilometres left before he was reeled in by Tour Down Under winner Stephen Williams.

But the Welshman was soon swamped by Tesfatsion, setting up the fight to the finish with Pithie.

The Cadel Evans Great Ocean Road Race -- named after Australia's four-time Olympic cyclist and 2011 Tour de France winner -- is the second event on the WorldTour following the six-stage Tour Down Under, won by Williams in Adelaide earlier this month.

With the start and finish at the Geelong waterfront, the course takes the riders out of Geelong before heading towards the coast before returning to Geelong.

The Geelong loop, tackled four times, includes the steep 20 percent gradient Challambra climb, before the riders head back to the waterfront for the final dash to the line.