Thirroul's Owen Wright impressed as big guns Mick Fanning and Joel Parkinson suffered shock defeats to be eliminated from the world surfing tour event in Tahiti.

The pair were both undone by far less-credentialed opponents in the third round of the Billabong Pro event in amazing 3-3.5 metre barrelling waves at Teahupo'o.

Former world champion Parkinson was the first to fall, stunned by American Brett Simpson, who fought back from a heavy early wipeout to post two high-scoring waves and snatch the lead.

Parkinson tried to find the score he needed to come back in the dying seconds of the heat but was beaten 16.23 to 13.17.

Defending world champion Fanning, fresh of a last-start win at Jeffreys Bay in South Africa, could only manage a single scoring wave as he went down to Australian Dion Atkinson.

The tour rookie's 9.50 wave lifted him to a two-wave score of 16.50, with Fanning only posting 5.94 in response to bow out.

"It feels bloody good," Atkinson said.

"I'm surfing for my survival but these guys are surfing for the title.

"I'm out there to win it, and I'm stoked I did."

Joining Atkinson in the fourth round will be fellow Australians Adrian Buchan, Bede Durbidge, Kai Otton and Wright, who eliminated fellow Aussie Matt Wilkinson.

World tour veteran Taj Burrow was another third-round casualty but 11-time world champion Kelly Slater made the most of his rival's slip-ups to ease into the last 12.

The American legend posted five nine-point rides in his heat, easily accounting for Brazil's Jadson Andre in the process.

"This is probably the best I've ever surfed 'Chopes'," Slater said.

The competition will resume, conditions permitting, on Tuesday. - AAP