Gabriel Medina and Caio Ibelli have collided mid-wave at the Rip Curl Pro in Portugal, sparking controversy over which surfer was in the wrong.
Medina was eliminated in the round of 16 on Sunday after being penalised for his part in the stunning collision.
The title race was blown wide open after the reigning world champion and tour leader was controversially upset by his fellow Brazilian.
Medina had been leading 14.34 to 7.17, but then in a moment of confusion started paddling his opponent's wave without priority.
He was sensationally docked all points for his lower-scoring wave to bring the scores back to 8.17 to 7.17, and Ibelli then managed to grab a 3.10 to knock a shell-shocked Medina out.
The 2014 and 2018 champion was filthy with the judges’ decision, calling for the verdict to be overturned.
“Caio and I caught the same wave and each went one way,” Medina said.
“My wave was shorter and his was longer. So much so that while I was back outside, he was still riding his wave.
“When I got out the back, I was so sure the priority was mine that I didn’t look at the priority sign. To my surprise, when the next wave came, I ended up going because I was sure the priority was mine.
“I ended making an interference. When I got out of the water I went to talk to the judges. We looked at the open images of the two of us paddling back to the bottom with an open camera angle. It was very clear that I arrived well before. And even if I had gotten along with him and had a draw, the priority would be mine by the rule.
“Because in the wave we surfed together before, Caio had priority one. I hope the situation will be re-evaluated because an error has occurred. I am still very hopeful that my heat will be reviewed.”
He also posted video footage of the incident to Instagram in an attempt to prove his point.
Ibelli said he felt sorry for his compatriot.
“I feel like surfing-wise he won the heat, but everything went my way. I have so much respect for him,” Ibelli said.
“I feel so bad, I mean I did my game and I came out with the win but he surfed pretty good.”
South American Jordy Smith, Brazilian Italo Ferreira and American Kolohe Andino remain in the title race in Portugal.
Fitzgibbons, Gilmore in Portugal quarters
Sally Fitzgibbons remains in the WSL title hunt after surfing into the quarter-finals.
The world No.3 was joined there by fellow Australian Steph Gilmore, while world No.1 Carissa Moore and second-placed Lakey Peterson also advanced, in 1-3 foot peaks at the world-class beach break of Supertubos, in central Portugal, on Sunday.
Fitzgibbons combined a big cutback with a smooth carve for a 6.10, to which she added a clean frontside wrap with a strong snap through the lip for a 6.57.
Her combination of 12.67 was enough to see her past Australian Keely Andrew's and into a last-eight clash with Brazilian Tatiana Weston-Webb, who beat Hawaiian Coco Ho, 14.67 to 10.60.
Moore, who has a 10,000-point lead over Fitzgibbons, will next face Frenchwoman Johanne Defay after sending New Zealander Paige Hareb packing with a 13.20 to 11.00 victory.
Defay edged Costa Rican Brisa Hennessy 10.66 to 9.54.
The other title contender Peterson thrashed Silvana Lima 13.43 to 8.54 to set up a quarter-final with Australian Nikki Van Dijk, who scored 12.40 to beat American Courtney Conologue by 0.06 points.
Meanwhile, Gilmore narrowly edged compatriot Macy Callaghan 13.07 to 12.13 to book a surf-off with American world No.5 Caroline Marks, who knocked out Australian Bronte Macauley 12.67 to 9.83.