Nate Diaz once smoked a joint at a UFC news conference. He once left a broken down contract negotiation at company headquarters and relieved himself outside next to a garbage bin.

He once brilliantly submitted an opponent with a triangle choke while shooting his middle fingers at the live broadcast cameras — “double fingers and a fully locked triangle,” shouted broadcaster Joe Rogan.

He once, along with Jorge Masvidal, inspired the UFC to create the one-time “Baddest Mother[Expletive]” championship belt. It was such a big deal Donald Trump showed up, the first U.S. President to ever attend an MMA card.

Diaz, 37, fought his way into the promotion 15 years ago by winning the reality show “Ultimate Fighter.” He’ll fight his way out Saturday when he takes on Tony Ferguson in the main event of UFC 279, fulfilling his contract and earning himself the professional freedom to do, as Diaz is wont, whatever the hell he feels like.

Keep fighting? Stop fighting? Fight Jake Paul? Return to the UFC one day? Just stick with his new fight promotion business (Real Fight, Inc.) to go along with his other business interests: the cannabis company, the clothing line and jiu jitsu training center he operates with his older brother, Nick?

Who knows? Maybe not even Diaz.

Even the end came with typical drama, although this time not of his making. He was supposed to fight the more formidable, at least on paper, Khamzat Chimaev at 170 pounds. However, the undefeated Chimaev didn’t come close to making weight Friday, so the UFC had to scramble to give Diaz more money and an opponent in Ferguson on a four-fight losing streak.

Here, on his second-to-last day, Diaz held the promotion over a barrel, just as he always wanted.

Completing his UFC contract might be Diaz’s greatest victory in the fight game. It’s something Hall of Fame talents with teams of lawyers have tried and failed through the years. The UFC always wins, is always able to force extensions and sign new deals to keep marquee stars locked in until they become replaceable.

This just doesn’t happen. Of course, Nate Diaz just doesn’t happen, either.

You could trace his MMA origins to a park near Tokay High School in Lodi, California, which Diaz attended for two years before dropping out. On this day, he was involved in a fight just off campus.

“Whole school, everybody there,” Diaz recalled.

That included Nick Diaz, even though he’d quit school after his freshman year. The brothers, along with sister Nina, were raised in and around Stockton, California, in a blue-collar Mexican American family. Backing down was never an option. This was just the latest scrap.

“We fought it out for a little while, nobody won,” Nate said. “We both just cracked each other a few times. It wasn’t a very crazy fight. The cops came, sent my name back to the school.”

The next morning, with Nate home due to suspension, Nick said he was leaving for training and Nate should join him.

“Nick said, ‘You better get your ass to the gym with me after that [expletive] ass performance,” Nate recalled. “I was like, ‘[expletive] you.’ But I grabbed my [expletive] and went.”

A career was born. This was around 2000, when the UFC was still banned by most states, not to mention on pay-per-view. Future UFC president Dana White was still working as a boxing instructor. The Diaz brothers had watched some early UFC cards on rented VHS tapes and become enthralled with jiu jitsu, but there was no long-term plan.

They would become big organic stars for this organically growing sport.

MMA is a chaotic endeavor, but many of its best come from stable backgrounds — NCAA All American wrestlers, Olympic champions or products of childhoods spent in strict gyms from Dagestan to Sao Paulo that turn them into multifaceted fighting machines.

The Diaz brothers took their training seriously; they are Gracie black belts in jiu jitsu. Yet their style is from the street, a combination of skill, stamina and the mentality of teenage dropouts with nothing to lose.

What their signature strike — the “Stockton Slap” — is designed to deliver is disrespect, not devastation. Their ability to bleed without concern, willingly accept massive punishment and force fighters to finish them while always punching back is perhaps beyond compare.

“He’s a [expletive] dog,” Masvidal said of Diaz after winning that “BMF belt” in 2019. “Those same shots, I’ve hit a lot of people, they fold like a lawn chair. You’ve literally got to kill that guy.”

Last year, Nate took a 24-minute beating at the hands of Leon Edwards that was so bloody Rogan said Diaz looked like “a horror movie.” Yet Diaz never stopped clowning, preening and flipping Edwards the bird — as well as moving forward — until he rocked Edwards with a final-minute left and nearly scored a massive upset. “He wobbled me,” Edward acknowledged.

Edwards was victorious on the scorecards but Diaz won the roar of the crowd even before giving out the address to the house party he was throwing later that night and saying everyone was welcome.

That is why Diaz remains such a big draw despite a 20-13 record and just one victory since 2016. He’s unpredictable. He’s authentic. He’s hysterical.

And he always delivers action. During one four-year, 14-fight stretch earlier in his career, many carried on Fox to huge audiences that can’t afford every pay-per-view, Diaz was awarded fight or submission of the night 10 times.

He cemented his legacy when he took a 2016 bout against Conor McGregor on 11 days' notice — dropping some 20 pounds in the process. He then withstood a round of heavy strikes to choke out McGregor, grab the microphone and declare, “I’m not surprised, mother[expletive].”

The moment, and the (cleaned-up) quote got some street art/mural treatment in downtown Stockton. The California State Assembly even gave him a celebratory proclamation. “They said I was a negative turned positive,” Diaz said.

The antihero. The rockstar. The utterly on the edge ethos of mixed martial arts boiled into one fighter. He became oddly irresistible for fans.

“I’m not a very likable looking person,” Diaz said. “If you see a picture of me at a fight, I’m never [expletive] happy … You want to tell your mom this is my favorite guy here? And you look on TV and I’m going, ‘[Expletive] you [expletive.]’ … People are like, ‘What is this guy, [mentally challenged]’. I’m not [mentally challenged].

“I’m just not listening to you unless you understand what I’m doing.”

What Diaz was doing was whatever he wanted. To him, every dollar earned was found money. He was, as noted, best known in school for his fights, not his grades. He laughs about being so disruptive that he even got booted out of Driver’s Ed. (“I was active in class,” he noted.)

Where Nate Diaz is without the UFC is anyone’s guess, but it probably wouldn’t include global fame or more money than he ever could have dreamed.

Yet the fortunes that came from the fight game didn’t really change him. Rather than continue to push for more, he looked at how much he had and saw the power in contentment.

He turned down fights that didn’t interest him. He sat out for years on end. He rarely did media interviews. He took up triathlon as a hobby and became obsessed with that sport; one of the toughest men on earth content to race through the California hills against weekend warrior investment bankers and soccer moms.

You couldn’t make him up. In a blood thirsty sport, he is a strict vegan who once at a news conference laughingly admitted that he didn’t know what the word “irony” meant.

“I come from a place with no money and you give me too much money,” Diaz said. “I don’t give a [expletive] about making more. I am doing better than I was ever supposed to do.”

Had he played the game, he could have been even richer. Instead he bristled at what he thought were company men, such as Conor McGregor, who he believed the UFC manufactured while celebrating his wildness.

“All he did was act like me and Nick with an Irish accent,” Diaz said.

At least for now, his UFC career will come to a close. At least publicly, White said there are no hard feelings, a rare concession in a multi-decade test of wills.

“He’s fought incredible wars for us,” White told Yahoo’s Kevin Iole. “He’s been a big part of this company for a very long time. What more could I ask of Nate Diaz? I wish him all the best in the world. It’s been fun.”

If Diaz comes back one day for a trilogy fight against McGregor (the Irishman won a close decision in the 2016 rematch), no one will be surprised.

First, though, comes Saturday. Whether he walks out victorious or leaking blood as a loser hardly matters. It’s not the result, it’s the respect, and Nate Diaz, this wholly unique fighting hero, is about to leave the UFC on his terms, finally in control of everything.