It doesn't matter that his belt is designated "interim," or that he's beaten just one opponent rated in the top 10, or that he's not American.
Ireland’s Conor McGregor officially elevated himself to the top floor of the
By generating an organization-record $7.2 million live gate, with UFC President Dana White projecting record pay-per-view sales, the confident, expressive McGregor, 26, expanded his reputation in a showing that tested his resolve.
After getting cut in the first round, then slipping from Mendes' attempt for a fight-ending chokehold late in the second, McGregor stood up and unleashed a flurry of blows, the most significant of which was a left to Mendes' jaw that knocked the UFC's top-ranked featherweight to the canvas.
Four McGregor punches later, the fight was stopped.
"At the weigh-in, I asked [Mendes], 'Just stand here and look me in the eye,' and he wouldn't," McGregor said at the post-fight news conference late Saturday. "So when we came face to face, I said, 'Let's see who takes the first back step now.' So I marched forward."
Sacramento's Mendes (17-3) previously lost twice to UFC featherweight champion Jose Aldo of Brazil. McGregor was supposed to fight Aldo on Saturday, but then the champion suffered a rib injury in training last month and withdrew from the bout.
McGregor continued to mock Aldo after his victory, claiming he fought Mendes with injuries worse than Aldo's.
"He should've made that walk," McGregor said. "I don't want to talk about him. Right now, this is my night."
The collision of McGregor and Aldo was taken "to another level" by McGregor's performance, White said.
UFC Chairman Lorenzo Fertitta told The Times in a text message he'll "possibly," place the bout at MGM Grand for its typical marquee card around New Year's Eve, on Jan. 2, expecting to "regroup on Monday and figure it out" with staff.
McGregor, boosted by thousands of flag-waving Irish who crossed the Atlantic to attend Saturday, claimed validation against skeptics who assessed his wise mouth was the biggest reason for his title shot.
He appeared to be in great trouble in the second round, his back to the canvas for an extended period as Mendes delivered good right elbows, forearms and fists to the Irishman's head.
"I knew the efficient man prevails in a fight to the death," McGregor said. "When I was on the mat, I was patient. I landed the shots that I could. I stayed safe. Every shot, I kept saying, 'Uh-uh, nope.' I felt I was preserving energy.
"I spoke to him in every exchange, that you're against a different animal now."
McGregor said his previous effectiveness with landing left hands and kicks to the body kept him encouraged as Mendes burned off seconds on top of him.
"I felt like I had complete control on top. I made the mistake of going for submission. I could've stayed there, and should have," Mendes said.
Sweat-soaked, McGregor slipped free and delivered Mendes a menacing glance as he stood, a follow-up to when he told Mendes earlier in the fight, "Is that all you've got?"
"The side kicks – to the naked eye, they don't look like much -- only me and the opponent know about 'em," McGregor said. "They suck rounds out of you. That's what happened. He was searching for his gas tank, and I was stabbing him in his gas tank.
"The fight went exactly as I thought it would, as it always does."
McGregor's wit has made him a media darling. He joked that while he tires of press commitments, those thoughts disappear when he collects a paycheck. His guaranteed purse was $500,000, and he's expected to earn a far greater cut in pay-per-view profits.
"When you have a guy who looks like you, talks like you, people rally around him. Conor has ignited the market," White said. "And the next one will be bigger."
Saturday's card was arguably the UFC's most entertaining in history, with comeback victories in each of the five pay-per-view fights.
In the welterweight championship, Robbie Lawler retained his belt despite trailing 39-37 on all three scorecards after four rounds, when he knocked out Canadian challenger Rory MacDonald one minute into the fifth round.
MacDonald broke his nose on a first-round punch by Lawler.
"Couldn't breathe, couldn't see," White said. "Yet, still landed 10 kicks."
MacDonald ultimately succumbed on another powerful Lawler punch to the nose.