Sonny Bill Williams was known for big hits on the rugby field, so when he hung up his boots, it was no surprise to see him lace up the boxing gloves again.

Williams started boxing long before his days as a cross-code superstar were over. Frankly, he needed the money. SBW had a $1 million AUD debt to pay off after he walked out mid-season on the NRL’s Canterbury Bulldogs to make his first foray into union with Tana Umaga’s Toulon back in 2008.

Read more: Joe Marler is in BBC’s Celebrity Traitors – here’s what we think and how to watch!

“I love boxing,” Williams tells Rugby World. “At the start it was through necessity because I was in $1 million debt and the guys who funded my start were boxers. So that is how it started and it lit a fire that I have not been able to extinguish.”

Anthony Mundine, a former rugby league star turned boxer, is one of Williams’s close friends. He’s also a mentor to him and fellow Muslim convert. A big name in Australian boxing, the former IBA super middleweight world champion lent Williams money to help him buy his way out of his five-year Bulldogs deal. And so it was on Mundine’s undercard that Williams made his debut in the ring, defeating Gary Gurr by TKO in Brisbane in 2009.

Williams won his first seven fights until 2015, when he stepped away from the ring to focus on representing the All Blacks at that year’s World Cup in England. He played a key role in helping them defeat Australia in the final.

During his first active period, Williams claimed the vacant New Zealand heavyweight title but he admits his talent definitely lies more on the footy field.

“A nice hit or a nice offload was always good but with boxing it is so uncomfortable for me. I didn’t grow up boxing, maybe a few fights at school, but everything about the boxing game is unfamiliar to me.

“When you go through it, you sit down and give yourself a quiet little pat on the back.”

Williams knocks out Ryan Hogan on Anthony Mundine’s undercard in Brisbane in 2010 (Getty Images)

It was only after Williams finished his second stint at the Sydney Roosters and decided to call time on a glittering career that he returned to the boxing ring in 2021.

Victories over Waikato Falefehi and Barry Hall followed before Williams lost every boxer’s prized possession: his unbeaten record. He suffered a shock defeat to MMA star Mark Hunt, a fellow Kiwi who is 11 years his senior. Williams was stopped in the fourth round in Sydney in 2022.

But how does defeat in the ring compare to a big rugby reverse? “It’s easier to get over a rugby loss than a boxing loss. I can share the heartache with 14 other guys. In the ring, it is just me.”

We meet Williams as he is preparing for his long-awaited bout with old rugby league rival Paul Gallen. The pair have been embroiled in a war of words for well over a decade but finally decided to settle their differences with a professional fight in July. “It is not in my blood to fight,” Williams insists. “It’s in my blood to be a soft teddy bear, as my wife would tell you. But the beauty of this fight against Paul Gallen and why it’s got me to this space, is because there is (real) skin in the game.

“I don’t really like the individual. He represents everything I hate about the system, how it works and how you get looked at in a certain way. I’ve got up for it.”

Williams looked sharp when we observed a training session in Brisbane during the Lions tour.

Read more: Sonny Bill Williams reveals the 2025 British & Irish Lion he would least like to face in the boxing ring

We even asked him which one of Andy Farrell’s tourists would fare best in a scrap inside the ropes… “I always say your tight five are ones to watch. To be honest, even your loose forwards, they are big, strong athletes. But I cannot look past my man Bundee Aki. He has something in him. He would probably be walking around in the second round blowing and then come with an overhand right and do something special – so it is my man Bundee.”

Whilst we have him talking about his old profession, how does Williams see the differences between rugby and boxing? “You ask the rugby boys how tough boxing is; hitting the bags is tough but try having someone punch you back (in the face).

“I’ve had a few big hits on the footy field and a few in the ring.

“I think the difference is in boxing I cannot rely on a Bundee Aki or Maro Itoje to help me – in the ring you are by yourself.

“Although I see it as a privilege as the one thing I miss from rugby is not the Tuesday and Thursday training or putting the balm on the knees to get ready, it’s the moment when you step on that field… before a World Cup final or a Super Rugby final.

“That massive sink or swim energy. That’s why I say this is a privilege (to still fight).”

Williams, now 40, lost to Gallen by split decision. He said it would be his last bout. Even the best don’t always get their fairytale finish.

This article first appeared in issue 315 (November 2025) of Rugby World magazine

Download the digital edition of Rugby World straight to your tablet or subscribe to the print edition to get the magazine delivered to your door.

Follow Rugby World on Facebook, Instagram and Twitter/X.