Sydney Roosters officials breathed a sigh of relief after Sonny Bill Williams survived a brawl with former heavyweight world champion Francois Botha to score a unanimous win at Brisbane Entertainment Centre.

With Channel Nine boss and influental Sydney Roosters supporter David Gyngell among a big crowd that included NRL operations manager Nathan McGuirk, Williams came through the bout unscathed for his premiership return on March 7 - besides a bloodied nose.

But the sight of Williams being rocked by Botha in the last round would have sent a scare into the Roosters camp.

Aferwards, Botha claimed he had won and challenged Williams to a re-match but the judges awarding the bout comfortably to Williams, with Steve Moore and Adam Height scoring it 97-91 and Alan Moore scoring 98-94.

''He is a fine gentleman but this is bullshit,'' the 44-year-old South African said.

Williams, who now holds the WBA international heavyweight belt, has aspirations to win higher honours but was unsure of his future in the ring.

''I am not sure, I will see how I go,'' said Williams.

It was just Williams's sixth fight but he showed in the opening round that he would not be overawed, leaving Botha with a cut on the bridge of his nose just before the bell rung.

A left hook in the second round opened another cut above Botha's right eye to give Williamms a target for the remainder of the fight.

With his superior speed and fitness, the former All Blacks superstar was able to easily pick off Botha with jabs to the head and body.

However, besides a brief flurry in the fourth round when he scored with a combination, found himself on the ropes and fought back with another combination, he seemed reluctant to move in for the kill.

In contrast, Botha hit referee Tony Kettlewell almost as many times as he did Williams - legitametly, at least - after missing and striking the official twice in the ninth round.

He also landed a number of late blows and was deducted a point.

But the experience of having been in the ring with the likes of Lennox Lewis, Mike Tyson and Evander Holyfield showed through and Botha had Williams in a bit of bother in the last.

Earlier, Wallabies star Quade Cooper took longer leaving the ring than he spent in it after knocking out Barry Dunnett in the first round of his boxing debut.

Cooper overcame nerves and an early shot from Dunnett before stopping the former martial arts exponent after 2.59 minutes with a right cross.

''I loved it. I was having so much fun in there I didn't want to get out,'' Cooper said. ''It just makes me want to get out there and do it again.''

- Sydney Morning Herald