During the middle of Sunday's finals against fellow Australian Julian Wilson, the defending champion was attacked by a shark.
"I was just sitting there and I felt something just get stuck in my leg rope, and I was kicking trying to get it away," Fanning said in the video.
Despite the scare, the three-time world champion wasn't going down without a fight.
"I just saw fins. I was waiting for the teeth to come at me. ...I punched it in the back," he said.
The competition was eventually suspended for the day.
YouTube, Sky News