The Australian made a late bid to shunt Hawaiian Sebastien Zietz into second and win his heat while eliminating Americans Michael Dunphy and Luke Davis four-to-six foot waves.
“The waves are a little smaller than yesterday (Tuesday), but they’re still perfect,” said Otton. “I think choosing the right ones are fundamental in these conditions. If you catch a good one, they’re going to open up and you can really let loose.
"But that heat was difficult because everybody surfed so well, especially Sebastien (Zietz) who gave me a hard time. For me, it was important to be able to qualify into the next round and keep my hopes alive of winning the event again.”
Another Australian, Perth Standlick, stood out from heat three after a single wave score of 9.60 put him into the next round.
Eighteen-year-old American Kolohe Andino also won his heat with a big score of 9.37 as he and Romain Cloitre saw off Billy Stairmand and Joan Duru.
“Yesterday (Tuesday) the waves were even bigger, but today it’s glassier with perfect sets coming in and I was able to show some of my ability,” said Andino.
“I was able to get two good waves and complete some more polished turns. Afterwards, I threw an air on the rights, but it was nothing special and I’m stoked to make it into the next round because the waves here are so good.”
Top seeded Alejo Muniz was dumped out of the tournament as ASP veteran Chris Ward and Jean da Silva progressed from their heat. Gabriel Villaran was also ousted.
“I caught such a good left that I thought I wasn’t going to be able to paddle into,” said Ward. “But I won the paddle battle and it was worth it because it opened up and was really good.
"I was stoked with the score the judges gave me and at the end I just stayed on the rights and tried to throw a couple of airs and just had fun until the horn sounded.”
Other notable fallers at this stage were Damien Hobgood, Patrick Gudauskas, Brett Simpson, Yadin Nicol, Heitor Alves Raoni Monteiro.
Winners of the round of 24 heats will progress directly to the round of 16, while surfers placing second and third will go into the round of 24.
No losers round of 24 match-ups:
Heat 1: Hizunome Bettero (BRA), Sebastien Zietz (HAW), Glenn Hall (IRL)
Heat 2: Kai Otton (AUS), Simao Romao (BRA), Perth Standlick (AUS)
Heat 3: Nat Young (USA), Jean da Silva (BRA), Kolohe Andino (USA)
Heat 4: Chris Ward (USA), Alex Ribeiro (BRA), Romain Cloitre (FRA)
Heat 5: Matt Wilkinson (AUS), Brian Toth (PRI), Flavio Nakagima (BRA)
Heat 6: Gabriel Medina (BRA), Jonathan Gonzalez (CNY), Willian Cardoso (BRA)
Heat 7: Wiggolly Dantas (BRA), Filipe Toledo (BRA), Keanu Asing (HAW)
Heat 8: Nathan Yeomans (USA), Yan Guimaraes (BRA), Leonardo Neves (BRA)