The assistance of Tony Mundine as well as some impressive sparring partners has put Sonny Bill Williams in prime shape for his New Zealand heavyweight title tussle with Clarence Tillman III on Wednesday.

Watch Sonny Bill Williams and Clarence Tillman III face-off at the weigh-ins [VIDEO]

Williams said he is feeling confident ahead of his fifth professional boxing match, which will see him take on a more experienced and bigger opponent.

“I feel in the last six weeks I’ve become a better fighter,” he said.

Former Australian champion Tony Mundine has been in charge of Williams, taking him back to “old school training”.

“I’m feeling really confident,” he said. “I want to put on a show.”

Williams has been sparring with Australian heavyweight champion Michael Kirby, as well as promising young Kiwi fighter Joe Parker.

On Wednesday night he faces Tillman, a 34-year old American-born pugilist with a professional record of 11 wins (six by knockout), eight losses and two draws from 21 fights. Tillman will be a decent test for Williams, a step up from his previous opponents and the rugby and NRL star knows it.

“He’s a big man, good with his hands,” Williams said.

“Taller and heavier than me. He’s got nothing to lose.”

Williams declined to give much away in terms of his plan for the fight, but clearly his speed and mobility will be key in this contest. Tillman won’t be easy to knockdown but with his height (1.96cm) and size (125kg) the New Orleans boy won’t be dancing around the ring either.

Williams could be expected to go for a win on points and it will be interesting to note how his development has continued. The 26-year-old has no amateur career to speak of so is still learning the fight game. But considering Tillman has been sparring with Kiwi cruiserweight Shane Cameron for this bout, and has previously sparred with the likes of Evander Holyfield and Chris Byrd, he should be no walk over.

Williams will also fight for 10 rounds for the first time his fledgling career, but fitness has never been a problem for the former Canterbury Bulldog.

“It’s a new challenge, I’m confident,” he said. “I’m fit enough to handle 10 rounds.”

Williams said his preparation for this bout has been “everything I could have asked for”.

An insight into how good his preparation has been, and far he might be able to go in the world of pugilism, will be revealed on Wednesday night.