All Black Williams beats Botha

World Cup-winning ex-All Black Sonny Bill Williams added another crown to his career Friday after beating veteran boxer Frans Botha to win their WBA International heavyweight title bout.

Williams, who won the Rugby World Cup with the All Blacks in 2011, survived a whirlwind finish from South African Botha to land the vacant title with a unanimous points decision over 10 rounds in Brisbane.

The ringside judges gave him the fight 97-91, 98-94, 97-91 over the 10 rounds to boos from the crowd.

Williams was holding on in the final round as 44-year-old Botha, dubbed the "White Buffalo", went after him with heavy blows.Williams, 27, who remains unbeaten in six fights, is due to play in Australia's National Rugby League this year with the Sydney Roosters.

Williams came through the bout unscathed for his NRL premiership return on March 7 - besides a bloodied nose.

Botha's record now stands at 48-10-3.

The South African has fought the likes of Lennox Lewis, Mike Tyson, Wladimir Klitschko and Evander Holyfield in a 23-year fight career.

Williams 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. I'll just keep plugging away, keep on doing what's keeping me happy," Williams said. "He caught me with a couple of good shots but thank God I stuck in there."

Wallabies flyhalf Quade Cooper won his first professional fight on the same fight card in a first-round knock-out of fellow Australian Barry Dunnett.

Cooper landed a right hook high on Dunnett's head to send his opponent crashing to the canvas inside the opening round of his scheduled four-round cruiserweight bout.

"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."