On Saturday night, with Tony Ferguson as the opponent after a bizarre, unprecedented several days, Diaz will leave the promotion as a winner, courtesy of a guillotine choke submission at 2 minutes, 52 seconds of the fourth round in the main event of UFC 279 at T-Mobile Arena.
And with that, the lore of Diaz -- one of the most popular, unconventional fighters in MMA history -- continues.
"I told them, 'Give me anybody you got,'" Diaz said in his postfight interview. "At least I got a worthy OG representative of mixed martial arts."
Diaz was originally supposed to fight Chimaev, but Chimaev missed weight by 7.5 pounds Friday, coming in at 178.5 for a 171-pound-limit bout. Diaz understandably opted not to fight an opponent who was so overweight. Diaz called Chimaev a "b---- ass rookie" and said he only trained wrestling during this camp, because Chimaev is a dominant wrestler.
Chimaev missing weight caused a chain reaction, with the UFC attempting to save the pay-per-view card. For most of the day Friday, promotion brass, including chief business officer Hunter Campbell and UFC president Dana White, worked to alter the top three fights. Ferguson agreed to fight Diaz in a five-round fight.
This was the final fight on Diaz's UFC contract, and he has indicated that he will not return to the promotion at this point. Earlier this week, Diaz's team announced he would be starting his own combat sports promotion, Real Fight Inc. Diaz has been in the UFC since 2007 and is an 18-year pro in mixed martial arts.
"I want to get out of the UFC for a minute and show all these UFC fighters how to take over and own another sport how you're supposed to do it," Diaz said, adding he meant boxing, kickboxing and Brazilian jiu-jitsu. "Conor McGregor didn't know how to do it. None of these other fighters know how to do it. I'm going to take over another profession and become the best at that."
And after that?
"Right the f--- back here to get another UFC title," Diaz said.
Diaz earned a $50,000 Performance of the Night bonus for the submission win. He has 16 of those in his UFC career, tied for the second-most in history, behind Donald Cerrone and Charles Oliveira, who each have 18.
Diaz vs. Ferguson was odd at times. Both guys clowned around at different points. Diaz leaned up against the cage, facing outward. Ferguson jokingly laid down on the mat unprompted. Both are veterans and fan favorites, each coming off the UFC's reality show "The Ultimate Fighter" as champions. Afterward, there was only respect, with the two embracing and bowing to each other.
"I kicked him in the shin, he was like, 'Owww,'" Ferguson said. "It was just a lot of having fun. I had fun in there. It was the coolest experience I could have had. It felt like I was back where I needed to be. I hadn't felt like that in a long time."
Ferguson said Diaz invited him to be a part of their camp and said, "I'm not going to say no to them."
"Those guys are pretty cool," Ferguson said. "We run California."
Judges Sal D'Amato and Ron McCarthy had Diaz ahead 30-27 going into the fourth round. Judge Junichiro Kamijo had Ferguson up 29-28.
Diaz (21-13) is a cult favorite who reached superstardom with a 2016 upset win over McGregor on short notice. A native of Stockton, California, he is 2-2 in his past four fights but nearly knocked out Leon Edwards -- who is now the UFC welterweight champion -- in his previous fight in June 2021.
"No matter what Nate does from here on out, this is his house," White said. "He's been here forever. It's been a blast having him here. I wish him well. He and I had this discussion months ago at the offices. Whatever he moves on to do, I wish him nothing but the best."
Ferguson (25-8) has dropped five in a row, most recently a knockout loss to Michael Chandler at UFC 274 in May. A native of Oxnard, California, he is a former UFC interim lightweight champion. Ferguson, 38, won 12 straight fights from 2013 to 2019, tied with Khabib Nurmagomedov for the UFC lightweight record streak.
Diaz joked that when Chimaev missed weight and the UFC asked him to change opponents, he told execs they "got to give me more [money] than you give any of the champions in this whole organization." Diaz said execs replied, "We already do," to which he said, "I want more than that, then."
"This is a crazy business, man," White said of the wild week with three fights changing. "It's a crazy business we're in. ... It's not as easy as it looks. A lot of guys say they want to get into the fight business -- be careful what you wish for."
And yet, despite all the chaos, Diaz ends up a victor yet again.
"I'm glad I got the job done," Diaz said. "Mission complete, for sure."