Tiara Brown produced the performance of her life to stun Skye Nicolson and win the WBC featherweight world title via split decision on away soil at the Qudos Bank Arena.

The build-up was a spicy one. Brown (19-0, 11 KOs) took shots at Nicolson's record and called her career a 'spoon-fed' one. Nicolson, on the other hand, told The Ring her opponent's resume was a 'joke'.

The pair exchanged plenty of verbal jabs with each other at the final press conference and at the weigh-in. Brown was said to be Nicolson's toughest test to date.

But in the end, Nicolson (12-1, 1 KO) was upset by Brown who walked away with a split decision victory with scores of 96-94 Nicolson, 96-94 Brown and 97-93 Brown on the undercard of George Kambosos Jr-Jake Wyllie in Sydney.

The first round was a cagey one as Nicolson, like she customarily does, took her time to read Brown's movements as her opponent came forward with jabs and right hands.

Brown's corner told her before the second round: "let your hands go." She did just that but Nicolson also increased her activity, landing a couple of sharp left hands to keep the American honest.

The third saw Brown land her best shot of the fight, a right hand as Nicolson, who struggled to get her jab going, was pulling away. The home fighter enjoyed a better end to the round, landing a couple of body shots and a left to the head.

The fourth was a little scrappier as Brown continued to push forward and negate Nicolson's jab. The Aussie landed with a big left but it was clear she wasn't as comfortable as she'd have liked. Nicolson's trainer Eddie Lam told her to keep at it with the body shots, but Brown was relentless in her work in the fifth round, stopping the home fighter from landing anything clean.

The scrappiness continued in the sixth as both women became tangled against the ropes, with Brown seemingly landing awkwardly on her ankle. When the pair came back together they elected to engage in a firefight, something Nicolson hasn't needed to resort to previously in her career.

Brown had more success in the seventh, landing a nice right hand before Nicolson came back with a left. The fight was more competitive than Nicolson had advertised, though, and in the eighth, the action remained just as close, with Brown continuing to march forward in search of power shots.

Nicolson had some success with her jab early in the ninth but Brown continued to do well in disrupting her opponent's rhythm. Looking for a stinger of a shot to change momentum heading in the final round, Nicolson's left came to her rescue in the final seconds, connecting with a peach.

Both women gave it their all in the final stanza, throwing more shots than they had in the previous nine. Nicolson held her feet and landed a couple of hard lefts but Brown wouldn't be deterred, putting in work on the inside and landing right hands on the chin.

After the bell, both fighters were raised aloft by the trainers. But it was Brown who was left in tears of joy on the floor while Skye was left to rue her lacklustre performance.

"Twenty years of wanting this moment, my composure and pressure won this fight, she's great at moving but my pressure won the fight," the new WBC 126-pound champion Brown said.

"She was holding a little bit but this is boxing, there's going to be some holding."

Eddie Hearn said: "She's the champ, it's her night tonight, we'd love to see if the WBC will give us the chance [of a rematch]."