It shapes as a defining clash in the Australia-based fighter's career, but that can also be said of Hunt's battles outside the cage recently.

After it was revealed that his UFC 200 opponent Brock Lesnar had tested positive to banned substances before their fight, Hunt has become a one-man army rallying against cheaters, dopers and his employers, the UFC, accusing them of turning a blind eye to Lesnar's transgressions.

Hunt is suing the UFC, a company that was sold last year for just over $4 billion - and he's still working, fighting for them, all the while daring them to fire him.

In many ways, his sudden change in attitude - transforming from an affable, genuinely quite funny fighter that was almost universally loved by fans for his knockout power and ability to absorb punishment into an unrelenting campaigner for fighter equality - has divided fans.

Some see him as the man finally ready to stand up to the UFC, while others consider he has a serious case of sour grapes after recent losses.

Hunt doesn't care.

All he wants is a level playing field.

In his UFC career, he's fought six times against men who have failed drug tests during their careers - Ben Rothwell, Bigfoot Silva twice, Brock Lesnar, Frank Mir and Alistair Overeem.

After his last fight, a knockout loss to Overeem, it was revealed the former K-1, Dream and Strikeforce champion was so sick before the fight he was admitted to hospital and administered an IV.

With intravenous fluids being banned by the Unites States Anti-Doping Agency, Hunt believes there is clearly different rules for different fighters.

"If you're going to make rules, make rules for everyone," he said.

"If you're sick you shouldn't be competing, don't use it as an excuse to get an IV and cheat.

"I broke my hand in one fight, that's a year out of work, the buy that tested positive got nine months, he was back fighting before I was."

Hunt has the utmost respect for Lewis, a man who has never been accused of doping in his career.

Riding a six-fight winning streak, the 32-year-old American is looking to surge into the top five of the heavyweight division.

In many ways, they're similar fighters. They both encountered trouble with the law in their youth, and both found combat sports - Lewis in boxing, Hunt in kickboxing - as a way to escape their circumstances.

Both found their way to MMA but retain aspects of their fighting origins, and this in particular appeals to Hunt, not particularly well known for his takedown defence.

A loss, for Hunt, probably isn't worth contemplating.

At 43, he's the elder statesman of the UFC, and if he moves to two losses and one no contest from his last three fights, his fighting future could be in jeopardy - especially as a man who is suing his employer.

Also on the card and looking to surge in the rankings are Queensland pair Damien Brown and Ben Nguyen, with Nguyen on the main card and Brown headlining the undercard.

Ranked 13 in the flyweight division, Nguyen was slated to fight one of the greatest flyweights to have ever pulled on the gloves in the form of Joseph Benavidez until the American pulled out with a hand injury.

His replacement, Tim Elliot, came close to submitting division kingpin Demetrious Johnson in his first UFC fight in two-and-a-half years after winning The Ultimate Fighter season 24.

Considered a submission specialist, Elliot will have his hands full with Nguyen, a striking powerhouse who proved in a loss against Louis Smolka that he is almost impossible to submit, and more than capable of holding his own on the ground.

Elliot put on a grappling clinic in his own fight with Smolka, earning both men $50,000 for their troubles in a fight of the night showcase.

A win would entrench Nguyen, originally from Sioux Falls in South Dakota but fighting out of Brisbane, in the top ten of a division where title challengers can come from literally any ranking.

For Brown, a former infantryman with the Australian Army, his clash with American Vinc Pichel is a change to build on his 2-1 record against a man who hasn't fought since 2014.

A large, rangy lightweight, it's not clear why Pinchel hasn't fought in three years but he's in for a torrid time against Brown, who is hell bent on moving up the UFC rankings.

Preliminary fights start at 10am AEST and the main card, also featuring Australians Dan Kelly and Alex Volkanovski, starts at 12pm.