Australian Jack Robinson has sent world No.1 John John Florence home from the Paris Olympics, riding tough in "super dangerous" surf to win their round-of-16 clash.
The much-feared break at Teahupo'o bared its teeth on Tuesday (AEST), forcing the women's heats to be called off for the day and a full postponement for Wednesday.
Robinson was dragged under at one point during his heat against Florence.
After the day's heats, organisers called the conditions "hazardous" and closed the venue for training.
Competition was then called off for Wednesday, with conditions potentially improving on Thursday.
In the deteriorating conditions on Tuesday, Ethan Ewing also advanced to set up an All-Australian quarter-final against Robinson.
A storm system south of French Polynesia made for terrifying action at Teahupo'o.
The wildness elevated the blockbuster Robinson-Florence heat between the World Surf League's number one and three ranked surfers.
In noticeably bigger surf than previous days, neither were able to put a meaningful score on the board in the first half of their 30-minute duel.
Chasing a wave, Robinson and Florence both disappeared into the wash and required rescuing from jetskis within seconds of each other.
Returning to the fray after being towed through the lagoon and back past the Pacific Ocean waves, Robinson recovered best.
The 26-year-old stood tall after dicing with the reef, plunging into a barrel to score 7.17 in a decisive ride.
A second score took the Western Australian out of reach of Florence, the two-time world champion, eventually winning 13.94-9.07.
"It's crazy. There are some huge waves out there," Robinson said.
"We didn't get an easy start of the heat. I got dragged over the bottom and almost had a two-wave hold down.
"It was one of those heats, you just have to have a lot of spirit and just keep pushing through.
"It's super dangerous. People don't realise it's the most dangerous place in the world in there, so just really happy to be in one piece."
Florence said he was flummoxed by the draw that allowed two of the world's top three in-form surfers to meet so early in the tournament.
"It sucks to come up against Jack this early on. One of us had to win and one of us had to lose. It's hard," said the Hawaiian great.
The result was a repeat of the Robinson's win from April's Margaret River Pro final.
Shortly after Robinson's progression, Ewing joined him in the last eight by defeating Australian-born Connor O'Leary, representing Japan.
Their heat resembled a battle to survive in the barrels, with both men taking all manner of tumbles, including one cringe-inducing face plant by O'Leary.
"I had some wipeouts but stoked it paid off ... I have so much water in my head right now. It feels good to be back on the land now," Ewing said.
Wave selection was paramount and Ewing did best: scoring an 8.67 with a deep run to defeat O'Leary 14.17 to 11.00.
The All-Australian quarter-final means both men cannot medal, but at least one will surf in the last four.
"It'll be cool," Ewing said of the match-up.
"He (Robinson) is definitely pushing the limits and one of the best guys out here, and that's where I want to be. So it will be exciting for sure."
Earlier, Joao Chianca triumphed in one of surfing's best heats at the Olympics, beating Morocco's Ramzi Boukhiam 18.10-17.80.
Chianca's reward is an all-Brazilian quarter-final with Gabriel Medina.
There will be three quarter-finals pitting compatriots against each other, with Tahitian Kauli Vaast, representing France, against Joan Duru.
The final quarter-final will feature Peru's Alonso Correa taking on Brazil's Reo Inaba, who progressed with a score of just 6.00.
When the women's draw resumes, Australian Tyler Wright will compete in the third round.
