George Kambosos Jr guaranteed himself a shot at a world title next after beating replacement opponent Jake Wyllie over 12 tough rounds in a DAZN main event at the Qudos Bank Arena in Sydney, Australia.

Kambosos Jr will now go on to fight Richardson Hitchins for the IBF junior-welterweight title in New York this summer.

"He's a tip-tap guy, I know he'll run. We'll get my cut fixed up and let's do [the Hitchins fight]," Kambosos Jr said on the Hitchins fight in the ring after his win.

"[Wyllie's] a tough kid, I knew he would be prepared, he's the best domestic fighter at 140-pounds, he's got a lot to look forward to in his future, good on him, hell of a fight," Kambosos Jr said after the bout. I would've loved to put him away but credit to him, we won."

Sydney's Kambosos Jr (22-3, 10 KOs) hadn't fought at home since 2016, so it was important to the home fighter he showed out and performed to expectations on a big night.

With a shot at 140-pound titlist Hitchins hanging in the balance, it wasn't the night to come up short - and though it was tougher than he expected, Kambosos Jr passed the test. The scores read 117-111 twice and 115-113 in favour of the 31-year-old.

Wyllie (16-2, 15 KOs) originally had tickets for tonight's event but was drafted in as a replacement for Daud Yordan on Monday after the Indonesian was pulled from the fight on medical grounds.

Queensland's Wyllie looked the bigger man in there from the opening bell and asserted himself well in the opening two minutes, landing a couple of stern jabs and a right hand. But by the end of the round, the action had swung the way of Kambosos Jr, who landed a flurry of swift left hands right on his inexperienced opponent's jaw.

Left hands were the order of the day for Kambosos Jr in the second as well. It became a shot that Wyllie simply could not defend if thrown with the speed and accuracy Kambosos Jr was doing so with.

More beautiful work followed from Kambosos Jr in the next round. The speed disparity was clear and for all of Wyllie's efforts in establishing his jab, he simply wasn't quick enough when the pair exchanged. The left hands continued, but Kambosos Jr also landed a peach of an uppercut which got his man's attention early in the third.

The fourth was better for Wyllie in the sense that he managed to avoid too many of those big left hands. But then Kambosos Jr mixed things up and changed levels by digging a few ripping shots to the body.

Wyllie had success in the fifth, landing a shot which caught Kambosos Jr on the button. It wasn't enough to win the round, though, as once again 'Ferocious' came back with his own attack, landing lefts and rights, even looking to have wobbled Wyllie at the end of the round.

The pair exchanged in the pocket in the sixth and Wyllie again enjoyed some action of his own, landing a couple of big right hands as Kambosos Jr dropped his hands. Wyllie also connected with some solid lefts to keep himself in a fight he previously struggled to get a foothold in.

In the seventh round, Kambosos Jr landed a nasty left hook on the inside but Wyllie was battle-worn at this point and kept coming forward with a sense his experienced foe was there to be got at.

Wyllie continued to connect at the beginning of the eighth but Kambosos Jr got himself back into the swing of things with a swift jab and left hand. Then came a right to the head and a left to the body to finish off Kambosos Jr's best round since the fifth.

But momentum shifted the way of Wyllie once again in the ninth after a clash of heads opened up a cut on the forehead of Kambosos Jr. Sensing his opponent could be in trouble, Wyllie stepped on the gas and landed two big right hands before shipping a couple of Kambosos Jr uppercuts in the ensuing attack.

Kambosos Jr came out with a vengeance in the 10th and had a round like one of his early ones, landing big left hands and uppercuts to keep a resurgent Wyllie at bay.

Clearly not in his DNA to be deterred, Wyllie came back with two clean right hands which got his opponent's attention but all it did was alert Kambosos Jr to the fact he needed to respond with something big of his own; a big left hand right on the bell.

The spoils were arguably shared in the 11th round. Both men had their success, Kambosos Jr with his left and Wyllie with his right.

The final round saw Wyllie, who looked the fresher man, leap off his stool and onto the attack from the off. In went a right hand before a left also connected for the underdog. Every effort was being made by the stand-in man to flip both fighters' careers on their heads.

Just before the final bell rang, both men elected to stand and trade and just seconds later they were embracing and congratulating each other on their efforts with the scorecards to come.

Kambosos Jr had done enough on the cards, winning two of them six rounds and the other by one. Onto the Hitchins fight 'at the end of June' it is for the Aussie, said Eddie Hearn after.

For Wyllie, Hearn guaranteed that the 24-year-old a Matchroom contract by Monday morning.