Mark Hunt celebrates victory over Sonny Bill Williams. Photo / Photosport

Sonny Bill Williams has suffered the first loss of his professional boxing career, going down to MMA legend Mark Hunt in a big upset.

Williams went into the fight with a 9-0 record having last beaten Barry Hall in March, while Hunt’s last outing was a loss to Paul Gallen in 2020. Williams is also 11 years younger.

However, that counted for nothing as Hunt claimed a TKO win over his fellow Kiwi, coming back after Williams was on top in the early rounds with some devastating blows in the fourth.

“Sorry about that, bro,” he said to Williams after the fight.

The cross-code superstar had started the fight well and appeared the better boxer before both Williams and Hunt opened the shoulders and started swinging hard in the third round.

Hunt is 48 years old but he still possesses immense power, as he showed in a wild fourth round.

He knocked Williams’ mouthguard out with a brutal right hand before dropping him with a couple of hooks.

“Sonny Bill is down,” commentator Andy Raymond said on Stan Sport.

“He’s hurt. Against the odds, Sonny Bill Williams has been dropped. His eyes are not clear.”

Williams survived the standing count but didn’t last much longer, as Hunt landed a powerful fight jab to his jaw and continued to hammer Williams with both hands against the ropes.

“Mark Hunt, in his final fight, stops the legend that is Sonny Bill Williams. What a fight,” Raymond said.

Australian boxing legend Danny Green added: “Wow, that was unbelievable.”

Williams was seeing stars and the referee had no choice but to stop the fight. The former rugby league and union star could scarcely believe it as he went down on his haunches in pain.

Hunt confirmed that he would be retiring on top, thanking everyone across Australia, New Zealand and the Pacific Islands, and noting that it was sweet to retire in his adopted home of Australia.

Joking that he didn’t like training at the best of times, Hunt said after 31 years in combat he deserves a rest, and it will be much deserves after finishing on a perfect note.

See how the fight unfolded below.

- with news.com.au