Bring back the biff: Classic footage emerges of young Sonny Bill Williams in brutal on-field scrap

These days, Sonny Bill Williams is the model professional sportsman.

But back in 2003, things were a little different.

Rare footage has emerged of 18-year-old Sonny Bill Williams engaged in a brutal on-field scrap during a match for the Junior Bulldogs against the Junior South Sydney Rabbitohs.

Williams was involved in some pushing and shoving following a penalty which led to the 6'4' 18-year-old delivering a devastating two punch combo which he was sent off for.

But the action didn't stop there. The Souths player was also sent off for his part in the fracas, and as he headed to the changing room, he ripped his shirt off and charged straight at Williams who was standing on the sideline.

Williams showed the speed and precision which would later form the basis for an impressive boxing career, with a sharp left jab to drop the oncoming opponent.

In 2002 Williams became the youngest player to ever sign with an NRL club after moving to Sydney and signing with the Bulldogs at 17-years old to play in the junior grades.

In 2004, at 19, Williams made his NRL debut.

Williams has been vocal about overcoming the struggles of his younger years, and maturing as a man/player and now father.

In an interview with the Guardian in 2013, Williams said: "The biggest thing to understand about me is that I moved [from Auckland] to Sydney when I was 15,".

"I was all by myself and that was the hardest thing because I like to stay at home with my family. I went from playing muck-around-footie to training intensely six days a week. I was also working as a labourer. I wake up and it's dark. I get home after training and it's dark. And I wouldn't say boo if I went into a room and two people were there. It took me a long while to get my confidence, bro."

Williams experienced premiership success in his debut season and became the youngest person to play for the Bulldogs in a grand final when playing off the bench in the Bulldogs' 16–13 victory over the Sydney Roosters in the 2004 NRL Grand Final.