George Kambosos, the unified lightweight champion of the world, takes on undefeated WBC champion Devin Haney for a chance to become unanimous on Sunday at Docklands.
It's arguably the biggest fight that's ever taken place on Australian soil and the first time all four belts will be on the line in the lightweight division.
The main event will be a cracker in itself, but the undercard is absolutely stacked as well.
Here's everything you need to know about Kambosos vs Haney.
Who is George Kambosos, unified lightweight champion?
Sydneysider George Kambosos, 28, simultaneously stunned the boxing world and backed up his rock-solid self-belief by beating Teófimo López at the Madison Square Garden Theatre in November last year.
Kambosos knocked López to the canvas in the first with a gorgeously-timed right and generally outboxed a man considered to be one of the best pound-for-pound fighters in the world.
That win caused a seismic shock to ripple through the red-hot lightweight division and put Kambosos firmly in the box seat.
Kambosos is still undefeated as a professional, with 20 wins from 20 fights (10 KOs).
He is the reigning IBF, WBO, WBA and The Ring champion — and also holds the WBC Franchise belt.
Who is Devin Haney?
Devin Haney, 23, is a terrific fighter who turned pro aged just 17 after a stellar amateur career in which he was crowned American national champion five times.
Haney was controversially crowned WBC champion in 2019, elevated to champion status when Vasiliy Lomachenko was named WBC Franchise champion — controversial in as far as he did not "win" the belt from anyone.
He has since defended his championship belt four times, most recently against JoJo Diaz in December last year.
Haney has a professional record of 27-0 with 15 KOs.
What has Kambosos said?
As is so often the case, the pre-flight build-up has been acrimonious on both sides.
Kambosos accused Haney of being a "rat", "snitch" and "informant" for providing him information in the lead-up to his fight against López.
Kambosos also derided Haney as only holding the WBC belt because Lomachanko gave it to him as a "present" after the Ukrainian was elevated to Franchise champion.
"I've had to go through every bit of adversity," Kambosos said.
Lomachanko also came up as the fighter Kambosos wanted to fight in his first defence, but was unable due to the Russia-Ukraine war.
He said Haney was a stop-gap and that he did not have anything Kambosos could not handle.
"The guy likes to run, he likes to move, nothing special, the holes are there," Kambosos said.
"I was there ringside [for the victory over Diaz] and almost fell asleep to be honest because it was that boring."
What has Haney said?
However, Haney has been nonplussed all week by Kambosos's "act", saying that he is a "class above" the Australian.
"When is the act going to stop? We can see right through it," Haney said.
Haney also described Kambosos as a "clown" for not bringing his belts to a press conference earlier in the week.
"There's nothing that he can do in the ring that's better than me," Haney said.
"I will show it on fight night.
After Saturday's weigh-in drama, Haney also said: "I'm a true champion, and true champions make weight."
Isn't Kambosos already undisputed?
No. Well, sort of, but not really.
Thanks to boxing's stunningly complex governance structure, Kambosos has a belt from each of the four major bodies.
However, his WBC Franchise belt is controversial, with most fans saying it is not the real championship, which is currently held by Haney.
Complicating matters is the fact that Haney did not win the belt in the conventional way and was only elevated into the position.
What we can say for sure though is that whoever wins on Sunday will definitely be undisputed — unless the WBA's regular champion Gervonta Davis wants to kick up a fuss, that is. (Kambosos is the Super champion).
Moloney brothers headline packed undercard
There are some big names on the undercard, as is befitting of such an enormous occasion.
Andrew and Jason Moloney will headline a massive card of boxing.
Andrew Moloney (23-2) will meet Alexander Espinoza (21-3-2) in an eight-round super flyweight contest.
Jason Moloney (23-2) will meet Aston Palicte (28-4-1) for the WBC silver and WBO international bantamweight titles.
Kiwi heavyweight Junior Fa (19-1) will take on Lucas Browne (30-3) for the WBA Oceania heavyweight title.
How can I watch the fight?
The entire card will be available on Fox Sports' pay per view channel, Main Event, which can also be accessed via Kayo.
It will cost $59.95.
When will Kambosos walk to the ring?
The pay-per-view coverage starts at 11am AEST, although the first fight is set for 9:30am.
Kambosos vs Haney will likely start sometime after 1:00pm AEST.
