Sonny Bill Williams sensationally knocked out in boxing ring by MMA fighter Mark Hunt

Sonny Bill Williams has lost the first professional fight of his boxing career after being sensationally knocked out by MMA fighter Mark Hunt.

SBW was the overwhelming favourite for the eight-round heavyweight bout against his 48-year-old opponent, but ‘Super Samoan’ Hunt pulled off an incredible fourth round upset.

Williams was in control of the first three rounds, landing numerous blows with a 50 percent success rate, as his opponent struggled to deal with the pace, landing just 20 percent of his limited punches.

However, despite looking fatigued, Hunt unloaded on the former rugby league star, who was 11 years younger and 20 killograms lighter, in a fourth round masterclass from the MMA fighter.

That weight advantage gave Hunt considerably more power as SBW was unable to withstand the blows, knocking down the cross-code great twice in the fourth, with the second knockdown proving to be decisive.

Williams came into the fight with a perfect 9-0-0 record, having claimed four knockdown wins in the process. Just a few weeks ago, his opponent Hunt weighed in at 157kg.

Hunt is a fighting man, having competed in 43 kickboxing fights, 29 MMA fights and three boxing fights prior to taking on Sonny Bill.

But having failed to win any of his three boxing bouts before taking on SBW, losing two and drawing the other, the veteran was expected to take a beating.

That didn’t materialise though and Williams was quick to pay credit to his opponent after the fight at the Aware Super Theatre in Sydney.

“I would just love to say it’s an honour to share the ring with you, the ‘Super Samoan’,” Williams said.

“It was humbling, I tried my best but he was too good for me.

“Whatever is written for me is written for me.”

Heavyweight Champion of the World Tyson Fury left a good luck message with Sonny Bill prior to the fight, but it was Hunt who was celebrating after in what is likely to be the final fight of his career.

“I caught him with a right uppercut,” Hunt said, reflecting on his win.

“I don’t know if it’s his chin, I might just have a lot of power. That’s heavyweight stuff, I carry a lot of weight.

“Heavyweights pack a lot of power, a shot like that could have ended anyone.”