While his aim is to stay there for more than just one night, it's safe to say that regardless of his future, the 23-year-old cemented himself a place in MMA history by authoring one of the sport's most incredible moments.
According to his striking coach, kickboxing great Duke Roufus, it was no accident. Roufus told MMA Fighting that it's a kick that was conceived a few years ago and practiced weekly by Pettis during training camp.
But did he expect him to actually pull it off?
"With Showtime, I don't doubt anything," Roufus said. "I have a lot of crazy theories in my head, and he trusted my theories and went with it. He had the heart and the courage to do it. That's the thing that makes great athletes great. If this is the NBA, and there was five seconds on the clock, he'd be the guy to want the ball.
"To his credit, anyone could have great ideas, but to have the guts to pull it off in the fifth round was incredible," Roufus continued. "He could've slipped and fell and given up a bad position. It was risky. But you know what? There's a saying: Fortune favors the bold."
Roufus said he felt "like a proud father" when Pettis landed the kick against Ben Henderson, and like most of the people watching in the arena and many watching from their couches at home, he immediately shot up to his feet in incredulity before a commission member had to remind him he needed to sit down.
The magnitude of the kick, however, goes even beyond the style points, as Henderson and Pettis were locked in a very close bout, and the knockdown likely sealed the round in the eyes of the judges. The win made him the WEC's final lightweight champ, and made him the No. 1 contender to the UFC's belt.
Both the championship and the kick are a major point of pride for Roufus, who admitted a deep interest in continuing to innovate the striking aspect of mixed martial arts. Roufus said that after a lifetime of fighting in rings in muay thai and kickboxing, transitioning into competing in a cage made him open his mind to new things. He said he originally got the idea a few years back just playing around with students during a class.
"There's lots of different techniques we do," the Milwaukee-based coach said. "We try to be as creative as possible. If there was no creativity, they'd still be running the option and the wishbone in football. I want to train my fighters to be hard to fight. Not only because they're aggressive and strong, but because they have a style that's hard to prepare for."
Both Roufus and Pettis said that the move came about because Henderson was hard to catch with kicks all night. Pettis set him up, baiting him with a ricochet move off the cage that changed speeds. Roufus equated it to "Allen Iverson's crossover move, back in the day."
It certainly fooled Henderson, who was backing away with his hands down as Pettis shot off the cage with a right foot that caught him on the left side, on the chin.
"The spring off the cage gives you a little boomerang action, which helps disguise it," he said.
In the time since, Pettis' kick has gone viral on the internet, made ESPN's "Top Plays" and has even been replayed by news outlets that usually have no interest in the sport, like CNN.
Pettis came in with two goals: winning a belt, and having a great match. Mission accomplished.
"He was trying to go for the finish, and be dynamic for the fans," Roufus said. "You want to be known by the fans, and make new ones. No one leaves Floyd Mayweather fights jumping for joy. We want to be known as action fighters and make highlight reels. He did. That's why he's Showtime, performing like that under the spotlight."
For Pettis, it's just the beginning. Besides his striking offense, he showed strong takedown defense against an accomplished wrestler in Henderson, and when he was taken down, he flashed a dangerous guard. Roufus says he has designs on becoming "a [Georges St. Pierre]-type character" in the way he evolves every part of his game to elite status.
And as for the kick that made him famous?
"I've got 10 more of those kicks coming when I'm in the UFC," Pettis said.