LOS ANGELES – On Saturday at Staples Center, for only the third time in UFC history, two unbeaten fighters will meet for the world title.
Ronda Rousey (10-0, 10 finishes) will defend the women's bantamweight title in the main event of UFC 184 against Cat Zingano (9-0, eight finishes).
The only other undefeated championship bouts in UFC history were Rashad Evans-Lyoto Machida for the light heavyweight title at UFC 98 in 2009 and Rousey-Sara McMann at UFC 170 last year.
The Rousey-Zingano fight will attract a horde of celebrities who are coming out to watch what could be the match that, 10 years from now, 25 years from now, 50 years from now, is the one that all other women's bouts are judged against.
Just as major boxing matches are measured by the standard of Muhammad Ali (31-0, 25 KOs) against Joe Frazier (26-0, 23 KOs) on March 8, 1971, it's possible that future women's MMA fights will be judged against Rousey-Zingano.
UFC president Dana White, who frequently raves about Rousey, is nearly as effusive in his praise of Zingano. He said that among the celebrities expected to attend are Jennifer Lopez; Demi Lovato; Will Smith and his wife, Jada Pinkett Smith; Mark Wahlberg; Maria Shriver; Ed Norton; Mandy Moore; Vin Diesel; Charlize Theron; Anthony Kiedis; Kellan Lutz; Schoolboy Q and Travis Barker, among others.
"A lot of celebrities we don't normally get," White said.
The card at one time looked as if it might be the most loaded of the year. The main event was supposed to feature a middleweight title bout between Chris Weidman and No. 1 contender Vitor Belfort, but Weidman injured a rib and the fight was moved to May 23.
Rousey-Zingano moved up to be the main event. But the Frank Mir-Antonio Silva fight was moved off the show to become the main event of the card earlier this week in Porto Alegre, Brazil, and a fascinating match between Jacare Souza and Yoel Romero was switched off when Souza got pneumonia.
That left Rousey-Zingano at the top of a far thinner card in terms of big names. And yet, the celebrities are still coming in, which in White's eyes is recognition of Rousey's stardom.
"She's the headliner," White said of Rousey. "She's the one who's getting pushed. She's the champion. She's the star. She's at such a high level that other celebrities recognize that, but it also has to do with the fight.
"It's a tough, legit fight. Cat Zingano is probably the greatest threat to Ronda there is. Do you remember that fight she had with Amanda Nunes, where she got her in that guillotine and then [suplexed her] backward? That kind of raw power and strength that Cat Zingano has, I've never seen in the women's division."
Rousey, who at 28 seems to be hitting her athletic prime, insists she's ready to raise her game to another level. Her history would suggest it's tough to bet against her, given the way she's added to her game virtually for every bout.
One of the marks of the greatest athletes in any sport is that they perform their best when the stakes are highest.
It doesn't get much bigger than facing another unbeaten opponent, particularly one who is as strong, powerful and aggressive as Zingano.
When Rousey began, her coach, Edmond Tarverdyan, spoke glowingly of her potential. Before her first UFC fight – a match at UFC 157 against Liz Carmouche that came amid great hype and fanfare – Tarverdyan told Yahoo Sports he felt Rousey's boxing had progressed so much that she was capable of winning a gold medal in that sport if she focused on it.
She stopped McMann with a knee to the midsection last February for her first finish other than an arm bar and pummeled Alexis Davis in just 16 seconds at UFC 175 on July 5.
Zingano, who lost a chance to fight Rousey earlier when she injured a knee that forced her to pull out of a coaching stint on "The Ultimate Fighter," said Rousey's dominance has, in an odd way, helped the division.
"She's great for the sport and for women's MMA," Zingano said of Rousey. "What she's done is that she's made all of us work harder and improve our games so we can get to that level. I have nothing but respect for her.
"But I also feel like I am the one to do this. Everybody talks about the arm bar and this and that, but I bring things to the table, too, that she has to worry about."
The bout could, in many ways, be a battle between Rousey's judo throws and Zingano's wrestling, as well as a battle of vastly different striking styles.
Rousey's hands are far better than they were two years ago, when she debuted in the UFC, and she throws with speed and in combination. Technically, her combinations may be sharper than Zingano's, but Zingano has the overwhelming power that could give her an edge.
"This is one of those fights that I absolutely can't wait to see," White said. "It's an awesome fight, in my opinion. A lot of people have been saying that Cat Zingano is the absolute biggest threat to Ronda's title. [UFC broadcaster] Joe Rogan was saying that Ronda isn't just a once-in-a-lifetime fighter, she's a once-in-an-ever fighter.
"To me, this is a fight that has everything you could want to see in a fight: two great athletes at the very top who have speed, power, great technique, great athletic ability and an incredible desire to win."