The incredible video of 34-year-old and three-time world surfing champion Mick Fanning walking away unscathed from a great white shark attack while competing in the final of the J-Bay Open at South Africa's Jeffreys Bay on Sunday has gone viral.

The live footages showed Fanning lying on his surfboard while waiting for the next wave, when a great white shark appeared from nowhere and approached the unsuspecting Australian surfer. His struggle with the shark was obscured by a wave, but he later reappeared without any injury before he was picked up by an emergency boat.

For his extraordinary calm and attitude, Fanning was described as both courageous and lucky.

He told World Surf League at the rescue boat, "I felt something grab, get stuck in my leg rope and instantly jump away. And it just kept coming at my board...I punched it in the back."

Fanning continued, "I'm totally fine, got nothing wrong with me. There's a small depression in my board and my leg wrap (was) bitten."

Shark expert Dr. Daniel Bucher, a lecturer in marine biology at Southern Cross University, attributed Fanning's survival instinct that saved his life when he realized he was under attack by a shark, reported the Daily Mail. Butcher listed four things that Fanning did right that saved his life.

1. He fought back

Dr Bucher said the shark, estimated to be at least six meter long, probably got scared when Fanning fought back. "Once the shark was having a go at him, facing it and trying to fight back is the sort of thing everyone would do instinctively. You want to put a bit of doubt in the shark's mind that if it keeps up the attack you might be able to hurt it." Bucher said.

2. He used his surfboard

In his narration of the event, Fanning said he was dragged underwater when the shark bit the leg rope of his surfboard. But his also allowed him to break free from his board. The board distracted the shark, Dr Bucher said.

He explained, "More than anything he was lucky the shark got caught in the leg rope, because that got the shark thinking twice. The board is still tugging on rope making it look like he got something bigger than he does.'

3. He did not trash around

Luckily for Fanning, he was not injured by the shark in the first attack and decided to leave him. Fanning grabbed this opportunity to call out for help, particularly attracting the attention of fellow Australian and world title rival Julian Wilson.

Dr Bucher said this was actually a very crucial time to survive during a shark attack because the shark could return and attack you again. He said, "The moment of the attack you would be full of adrenaline and you wouldn't be thinking too much. I think after the first attack you have to get out of there while the shark's having a think. You have to try not to splash around too much or you'll look like an injured animal."

4. He got out of the water quickly

Before the rescue boat reached Fanning, the Australian surfer quickly tried to bodysurf a wave that minimized splashing. Dr Bucher said it is important to quickly catch a wave because it is very difficult to swim fast without splashing the water.

The World Surf League quickly cancelled the remainder of the event and declared Fanning and Wilson to share second place and split the prize money, said CS Monitor.

The World Surf League said in a statement, "We are incredibly grateful that no one was seriously injured today. Mick's composure and quick acting in the face of a terrifying situation was nothing short of heroic and the rapid response of our Water Safety personnel was commendable - they are truly world class at what they do."