By Chris Barclay

Adding punch to the Chiefs and All Blacks backline is now Sonny Bill Williams' priority after a bid to rebuild his reputation as a professional boxer ended with a successful outcome in Sydney on Saturday night.

Williams recorded a clinical unanimous points decision over 137kg American Chauncy Welliver in a frustrating main event at the Footy Show Fight Night - and now he is eyeing another "heavyweight" rematch with former NRL adversary Israel Folau.

The code-switching footballers could share the same field for the first time since the Bulldogs regular season clash with the Melbourne Storm in 2007 when the Waratahs host the Chiefs in their final Super Rugby pre-season trial in Sydney on Friday night.

Williams, who emerged unscathed from an eight-round fight-cum-wrestle with a 71-bout spoiler, expressed a desire to turn out for the Chiefs for the first time since they won their inaugural Super Rugby title in 2012.

"It's full focus on rugby now," said Williams who wore a Chiefs tank top into the ring at Allphones Arena.

Williams featured in all four tests on the All Blacks 2014 end-of-year tour - shortly after departing the Sydney Roosters - and is anxious to face the reigning champions and play the opening round against the Blues on February 14 now boxing no longer takes precedence.

"I'm really keen, I need as much rugby as I can get," said the 29-year-old after Welliver attempted to used his vast experience - and 30kg weight advantage - to drive Williams to distraction.

Williams, who needed a drama-free victory to atone for a controversial win over South African veteran Frans Botha in his previous fight two years ago, won comfortably, and believed he was improving as a boxer.

"I know I'm no world beater but people who know boxing know he [Welliver] is no slouch. I'm trying to improve and hopefully I showed that."

Unbeaten in seven fights, Williams was most pleased to avoid the punishment Botha unleashed in the latter stages of their contest as he tired.

"Keeping defensively tight was the main thing. I felt like I only got glancing blows and I was riding the punches," he said.

Williams and team-mate Liam Messam, who launched his heavyweight career with a unanimous decision over Australian Rhys Sullivan, returned to Hamilton yesterday.

The 23-test All Black midfielder was noticeably coy before his comeback against Welliver and would not make any bold predictions about the next phase of his rugby career, a season which culminates with the All Blacks' World Cup defence in England.

"Hopefully be successful," he said, when quizzed on his goals for 2015.

"I'm at a time in my life . . . [where] sport's sport. I've been blessed to have a daughter [Imaan] 10 weeks ago.

"I've changed a lot of nappies, had a lot of sleepless nights but I love it. It's really changed my mindset about where sport sits in my life.

"I'm no less determined to do what I'm trying to achieve. If it goes well it goes well, if it doesn't it doesn't," he said, aware Malakai Fekitoa's emergence has added to the All Blacks midfield options.

"When I finish my sporting career it's not about what I've done, or being remembered as a legend. For me it's just about being the best father, husband and man I can be.

"At the end of a hard day's work I'm happy to have my daughter know the sound of my voice or see my first smile when she sees me."

Meanwhile, Williams's mentor Anthony Mundine reckoned a long mooted fight between Williams and NSW and Cronulla captain Paul Gallen - who improved to 3-0 with a unanimous decision over Randall Rayment was at least two years away.

"Sonny's got a bit more experience than Gallen. In a couple of years that'll be a good fight. Twelve months is unrealistic," he said.