The Kiwi star was sitting at home in the suburb of Botany, when a car crashed into a nearby house.
Tuivasa-Sheck immediately stopped playing a computer game, and went outside to see what had happened.
Once outside, he pulled a male passenger from the car, driven by a 34-year-old woman, which had ploughed into a neighbour’s house.
He then remained with the accident victims and the occupants of the house until the emergency services arrived.
“All I heard was a massive skid and a loud bang,” Tuivasa-Sheck told reporters Down Under.
“I helped him out, the cops have done their stuff and I went back in and played my game.
“I thought someone was clowning around but when I heard the bang, I thought ‘something’s wrong’.
“It wasn’t spectacular, I just opened the door and gave him a hand.
“He was a bit shaky. He had cuts all over his neck and face.”