LAS VEGAS — Israel Adesanya has been branded a “clown” by South Africa’s Dricus Du Plessis after storming the cage and ranting about him being a “n…er” – all of which could prove the prelude to a blockbuster UFC 293 headliner in Sydney on September 10.

Australia’s $300 million UFC showcase slated for Sydney this September is suddenly without a hometown headliner — but potentially two UFC arch rivals — after Sydney superstar Robert Whittaker was sensationally upset at UFC 290.

In a huge boilover here in Las Vegas, Whittaker was stopped by Du Plessis after being dropped twice in the second round and eventually finished on the ground with a series of big strikes.

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Australia’s first UFC champion was fighting for the right to face UFC middleweight king Israel Adesanya at UFC 293 in Sydney on September 10.

That opportunity, however, now belongs to Du Plessis, however immediately after Sunday’s fight the new contender refused to say if nine weeks would be enough time for him to get ready.

He did, however, have plenty to say about Adesanya, who had been watching his fight from cageside among a crowd including Donald Trump, Mel Gibson, David Spade, Chuck Liddell, even a masked Rey Mysterio Jr.

After the fight was done, Adesanya marched up and butted heads with Du Plessis before launching into a tirade which started: “This is my African brother right here. Let’s go n****r, what’s up b***h? Let’s go n****r. Yeah n****r. What’s up n****r. What the f*** you gonna do n****r?”

Despite the drama, UFC president Dana White shrugged off the Adesanya rant when asked about it last night.

Quizzed on allowing Adesanya into the cage, he said: “First of all, what I don’t like to do when you have someone like Dricus Du Plessis, big win for him, just beat the second best guy in the world, then somebody gets in their face, gets aggressive with them after they’ve just got done getting out of a war.

“So Adesanya and I had a debate over it and he promised me nothing crazy would happen.”

Asked by a US journalist about the racial comments, he said: “So what was racial?”

Told Adesanya called him the n-word, several times, the UFC boss continued: “He’s black. Who gives a s…?

“I couldn’t care less.

“This is the fight business. Israel Adesanya can say whatever he wants to say, who gives a s…?

“Are they bitching about that?”

Told some were, he continued: “Of course they are. Too f…ing bad.”

Asked soon after he was ready for everything Adesanya would bring to a Sydney headliner, Du Plessis said: “You saw tonight, that I’m prepared.

“I’m prepared for anything he says.

“He was carrying on like a clown in there.

“That’s not how a champion behaves. That’s not how a man behaves.

“He’s going on like child.

“Conduct yourself like a champion.

“There’s people looking up to you and you’re behaving like that? No.

“If that sells tickets good for him.

“I’ll sell tickets my way. I’m a gentleman, I’m a man and I’ll behave like a man.”

Exactly who headlines the Sydney event is hard to say, given Whittaker is gone from the title fight and Alexander Volkanovski revealed after his UFC 290 title win that he now needs surgery.

Enter Du Plessis.

Asked later how a fight against Adesanya goes, he continued: “I’ll knock him out just like I did tonight.

“We saw his fight with Alex Pereira. If I get him to the floor it’s not even a fight. If I get my hands on him it’s not even a fight.

“I will manhandle him.

“I’ve done it befor and I’ll do it again.

“And as far as his striking goes, OK, you are as good as your last performance. How was his last performance against Whittaker?

“Yeah, he beat him. It was a close fight.

“But how was my last performance against Whittaker?

“So right now that’s how I plan on beating him. The same way I beat Whittaker tonight.

“Implementing a game plan, sticking to my style and doing what I do best, listening to my coaches.

“We’re from a small gym in South Africa coming up with this style, this awkward style that looks completely wrong to so many people … but I’m the No.1 contender in the world right now so put some respect on that.”

Of course, here is no guarantee that, having upset his way into the biggest opportunity of his life, Du Plessis will be able to turn around on nine weeks notice.

White said it was too soon to say if Adesanya versus Du Plessis would be a goer for UFC 293, adding the South African could take “a couple of weeks” to decide.

Du Plessis also said it was too early to make a call.

All of which leaves questions over exactly who fights in Sydney.

Earlier this week it was announced Australia’s UFC cult favourite Tai Tuivasa will face fellow heavyweight contender Alexander Volkov.

Aussie Casey O’Neill and New Zealander Kai Kara-France have also signed on for fights.

If Du Plessis does agree however, the headliner will be one of the most anticipated fights of the year, and on the first of what will be three Sydney cards worth an estimated $300 million to NSW.

Earlier this year, NSW premier Chris Minns signed a massive UFC deal that will bring a trio of big fights to the Harbour City over the next four years.

Unfortunately for Aussie fans however, it won’t be Whittaker.

Arriving to the cage via his signature ‘Can’t Be Touched’ walkout, the Aussie landed some heavy shots early and took Du Plessis down with only two minutes gone.

The South African soon found his feet however — and then plenty more — taking Whittaker down himself with 50 seconds to go.

It was here the underdog landed some big elbows which cut the Aussie above the right eye and left him to finish the round bloodied.

Before the second too, Du Plessis raised his arms and urged the crowd to cheer as the fighters restarted proceedings that were quickly dominated by the South African.

Dropping Whittaker twice, Du Plessis then swarmed as Whittaker slumped against the cage wall and was finished on the ground.

While the Sydneysider seemed untroubled as he left the Octagon except for that cut and some swelling under his left eye, he was still taken to hospital for precautionary head and face checks.