On Saturday night at Hulu Theater in New York's Madison Square Garden, Australia’s George Kambosos pulled one of biggest upsets in recent memory, when he picked up a twelve round split decision win over Teofimo Lopez to capture the WBO, IBF, WBA lightweight titles.

The scores were 115-111 and 115-112 for Kambosos, while a third judge saw it 114-113 for Lopez.

Kambosos beat the man who beat the man - which he believes now makes him the man at 135-pounds.

“Have I changed all week? Have I changed all career? Never… I’m not the king, because you’ve got four kings [at 135]. I’m the emperor!” Kambosos said. “I’m the greatest fighter in Australian history.

"This is for my kids, my grandfather George Kambosos, who passed away two months away. It's for my family, my wife, my grandfather. I know he's in the ring with me right now."

Lopez complained over the scoring and felt that he was robbed in the fight - but Kambosos is more than willing to do the fight again.

"I won the fight fair and square. Take a look at your face. Take it like a champ, let's do it again in Australia," Kambosos said. "Eighty-thousand fans in Australia, let's do it again."

Kambosos has won all of his key fights on the road, traveling to other countries to make a name for himself.

"That's something these other guys in Australia who are making a bit of noise, they talk a big game and say they want to come over here but when it comes to booking that flight, they don't," Kambosos told AAP.

"So I don't understand how everyone wants to get behind them but they don't want to get overseas and chase it where it really happens, chase the big fish. It's a big difference when you're comfortable in your own zone and you need to leave your comfort zone and take the risk and achieve and get to the top and achieve what it is to become a world champion.

"They don't want to do it but Kambosos has done it and has been doing it for many years. We're here, we're fighting for the biggest thing Australia has ever seen. It's the pinnacle of the sport."