Conor McGregor triumphantly returned with a 40-second TKO of Donald Cerrone on Saturday night in the welterweight main event of UFC 246 at T-Mobile Arena in Las Vegas.
Here are 5 takeaways from the promotion's first pay-per-view card of the decade.
McGregor promised to return to full form in his bout against Cerrone, and he did just that.
It's tough to argue McGregor's win wasn't impressive. He took more than a year off after his loss to Khabib Nurmagomedov and hadn't won since November 2016, but it looked like McGregor hadn't missed a beat. It was a promising start to his 2020 "season."
Some people won't give him enough credit for the win because Cerrone's best days are likely behind him, but few fighters have been able to do what McGregor did to Cowboy. It was a perfect performance - and one that McGregor badly needed.
There were plenty of doubters heading into this fight - understandably so, given the time off and McGregor's legal troubles outside the cage. People weren't sure if they should believe McGregor's claim that he was really back. After all, it wasn't even clear he'd ever return to the sport before the Cerrone fight was announced just two months ago.
It'll be interesting to see how McGregor does against steeper competition moving forward, but "The Notorious" certainly looked like his old self - the fighter who won two belts and was on top of the world four years ago - in his return.
It's tough to describe Aleksei Oleinik's game. It's far different than anyone else's. But that's what makes the heavyweight contender so special, and why fans should treasure him all the more.
The American Top Team product defeated prospect Maurice Greene via second-round submission on the main card. Oleinik controlled his opponent on the ground with his elite grappling, finally locking in an armbar for his first win since September 2018.
Oleinik's game isn't pretty, but it's effective and usually impressive. Though he's not the most technical striker, it's tough for opponents to survive his onslaught of submission attempts if he gets hold of them on the mat. The veteran attacks from all angles, which is why the large majority of his 58 pro wins have come on the ground.
At 42 years old, Oleinik won't be around much longer, so enjoy his fights while you can.
Enter Diego Ferreira.
The Brazilian tapped out former UFC lightweight champion Anthony Pettis to record the biggest win of his career, and he's here to stay.
Ferreira has had a quiet rise, mostly because of the stacked nature of his division. He's also not big into trash-talking.
Ferreira, 35, has arguably been underrated for a while; he's beaten some tough competition and has only lost to top contenders. But he's never had a big-name win on his resume - until now. The submission of Pettis will allow Ferreira to break through as the newest contender at 155 pounds and let everyone know he's finally arrived.
There's nothing bad about 21-year-old prospect Maycee Barber losing to Roxanne Modafferi.
Everyone loses eventually, and one would think it's better to get that first defeat out of the way sooner than later. Barber can learn and grow from it that way, improving as a fighter as she progresses through the women's flyweight division.
Make no mistake: Barber is still a threat at 125 pounds. She can still fight for the title, and maybe even be a UFC champion one day. She's still years away from her athletic prime.
At the same time, can we get a little respect for Modafferi? She was way too big an underdog. Modafferi has been fighting as a pro since 2003, and she's a true pioneer of women's MMA. She may never get the title, but she's still one of the top fighters in the division. In hindsight, it's no surprise she was the one to set back the undefeated prospect.
Drew Dober has been around for what feels like forever, but it's never seemed like he'd be able to make serious waves in the stacked lightweight division - until now.
The 31-year-old put away top prospect Nasrat Haqparast early in the first round of their preliminary bout, shocking the world and silencing any critics he may have had.
Haqparast was coming off three straight wins and was considered one of the next big deals at 155 pounds.
But Dober, who's now 5-1 in his past six outings, stole his opponent's spotlight in the blink of an eye, and it seems like he'll finally start to get some respect. He called for a ranked opponent after the victory, and if he gets his wish, big things could lie ahead.