The triple world surfing champion was contesting the final when a shark surfaced and knocked him off his board.
Fanning had to fight the shark away before escaping with his life and miraculously survived any serious injury.
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"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," said Fanning.
"I just saw fins. I was waiting for the teeth."
Fanning added that he managed to "get a punch into its back", adding: "I instantly just jumped and he kept coming at my board. I was just kicking and screaming.
“I punched him in the back!”
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