JOHANNESBURG >> Knocked off his board by an attacking shark, a surfer punched the creature before escaping unharmed during the televised finals of a world surfing competition in South Africa on Sunday.

Three-time world champion Australian surfer Mick Fanning was struck by the shark from behind and knocked into the water as he sat on his board waiting his turn during the JBay Open in Jeffrey’s Bay in the Eastern Cape Province.

As he scans the water, two fins appear and with a splash he disappears under the surface. He is next seen furiously trying to swim to safety before a rescuer pulls him out of the water.

"A big sigh of relief seeing Fanning in one piece," a commentator is heard saying, on the video of the event posted on the World Surf League website.

"I felt something grab, get stuck in my leg rope and instantly jump away. And it just kept coming at my board,"Fanning said, once safe on the rescue boat.

Fanning said at first he swam away but then decided to defend himself and turned to punch the shark in the back.

"I saw it taking my board away and I just started cracking it," he told a crowd that gathered around him once he was back on shore, referring to how he struck the shark.

"I’m totally fine. I’ve got nothing wrong with me," Fanning said in an interview. "There’s a small depression in my board and my leg wrap (was) bitten. I’m just totally tripping out. To walk away from that, I’m just so stoked. Oh man."

The World Surf League cancelled the remainder of the event and Fanning will split the prize money with fellow Australian surfer Julian Wilson, who was also in the water when the attack happened. The two will share second place.

"We are incredibly grateful that no one was seriously injured today," the league said in a statement. "Mick’s composure and quick acting in the face of a terrifying situation was nothing short of heroic."

Commentator Ross Williams said there are occasionally shark sightings in and around events but an actual attack was very unusual.

"For it to happen in that fashion during the finals, where it actually showed that crazy aggression toward MickFanning, such a crazy thing," he said on the video.