Conor McGregor answered his critics with a blistering knockout of Donald Cerrone - brushing aside 'The Cowboy' in under 40 seconds at UFC 246.
In only his second bout since 2016 - a gap filled by outside-the-cage troubles - the Irishman returned to the Octagon with a bang.
The former two-division champion busted the nose of Cerrone in the fight's first skirmish before finishing him in a first-round TKO.
McGregor had not won since November 2016 when he stopped Eddie Alvarez, the lightweight, to become the first fighter in UFC history to hold two championship belts at the same time. McGregor then fought only his boxing match with Floyd Mayweather in 2017 before losing a one-sided UFC bout to lightweight champion Khabib Nurmagomedov in 2018.
But last night he leapt on top of the cage wall to celebrate with the thousands of fans in the T-Mobile Arena in Las Vegas.
"I made history here tonight, McGregor said. "I set another record. I'm the first fighter in UFC history to get knockout victories at featherweight, at lightweight and now welterweight."
"Donald holds the record for the most head kick knockouts so I was very very happy to get one myself. Thank you all for the support!"
Cerrone never got started. McGregor missed a left cross in the first few seconds and that was Cerrone's best moment. McGregor then used his shoulder to pop the American's nose before landing a brutal head kick.
Watched by celebrities including Matthew McConaughey, Jeremy Renner and Dave Bautista, and NFL star Tom Brady, McGregor then finished Cerrone with a flurry of punches on the ground before the referee called it off.
"He wasn't expecting that," McGregor said of the kick. "I'm so happy. I'm very proud of that accomplishment. UFC can strip fighters and give other fighters make believes belts but they can't give out knockout victories across multiple weight divisions.
"Etch my name in history one more time."
An incredible win for McGregor
Three years without a victory - but it didn't look like it. Conor McGregor may have silenced some of his doubters tonight with a blink-and-you'll-miss-it performance of speed and brutality. Welcome back, Conor.
That's it from us but you can follow reaction from Gareth on the Telegraph's special MMA page. Good night!
Cerrone taken to hospital
Reports coming in that Donald Cerrone has been taken to hospital. He will not be attending the post-fight press conference.
'A massive comeback. McGregor looked fantastic'
That's Gareth's verdict from the media room in Vegas. McGregor is very much back.
Heres my immediate post fight #ufc246 analysis - i believe @TheNotoriousMMA fight @GamebredFighter in July and @MannyPacquiao by the end of the year promoted by @FloydMayweather and @danawhite and the @ufcpic.twitter.com/tBWnIIdLuv— Gareth A Davies (@GarethADaviesDT) January 19, 2020
'I've never seen anything like that'
It's fair to say Donald Cerrone is in shock.
The Cowboy is telling the crowd that he didn't see those shoulder hits coming. He looks bewildered.
Cerrone dismantled too easily
GAD in Las Vegas: It may have been 40 seconds - but the truth is we did not learn if McGregor has really been affected by the 15 months away... Cerrone was dismantled easily. It would have been good to see the Irishman pressed more, but in fairness he did nothing wrong and everything clinically.
Right. Who doubted him?
Own up. Who backed against McGregor? What an incredible performance by a superstar of the sport.
Such drama... was that even 30 seconds?
Gareth A Davies in Las Vegas: Round 1. Such drama... They immediately clinch. Cowboy is cut and McGregor lands a a huge left headkick and attacks Cerrone who collapses under the weight of punches. Referee Herb Dean steps in to separate them. The fight is over. The Mac is back... Was that even 30 seconds ... ?
McGregor immediately broke Cerrone's nose with a shoulder strike - almost the first hit of the bout. Then the Irishman caught Cerrone with a left high kick, right on the jaw, and swooped in to pummel the Cowboy.
IT'S ALL OVER!
Unbelievable. McGregor wins in seconds.
Here we go...
Moody music and a hop, skip and jump from the MMA superstar.
Here comes the Cowboy
Donald Cerrone enters the arena to a few boos...
Electric atmosphere in Vegas
Video: What Cerrone needs to do
I do hope The Telegraph lawyers aren't watching this, Gareth.
Video: How McGregor can win
Gareth A Davies demonstrates how Conor McGregor should approach this bout by giving some poor chap a hiding:
Slick arrival for The Cowboy
Matthew McConaughey joins the party
A must-win fight for McGregor
Fury goes with McGregor
Time with @Tyson_Fury earlier today at @trboxing office of the esteemed @BobArum the 88 yeara young promoter (Huge @TelegraphSport@Telegraph interview next week ������) but Fury has picked @TheNotoriousMMA to defeat @Cowboycerrone by TKO pic.twitter.com/KCQRaDy0ZN— Gareth A Davies (@GarethADaviesDT) January 19, 2020
'It doesn't get more American than a cowboy vs an Irishman'
Duke Roufus, the MMA coach, says tonight's fight will be an "awesome" match-up of styles.
McGregor has arrived
Holly Holm: 'This is a wild-card fight'
Gareth A Davies grabbed a moment with Holly Holm to ask her how tonight's bigfight might go...
At @ufc#ufc246@HollyHolm is up soon in what should be a high level womens 135lb fight with @RockyPMMA ...— Gareth A Davies (@GarethADaviesDT) January 19, 2020
Here's Holm predicting @TheNotoriousMMA vs @Cowboycerrone for me ... pic.twitter.com/88tRWDM13y
Modafferi causes an upset
GAD in Las Vegas: Earlier tonight there was a significant result in the women's flyweight division. Maycee Barber has risen fast, and at the age of 21, wanted to become the youngest champion ever, breaking Jon Bones Jones's record. But her opponent Roxanne Modafferi outfought her, winning by unanimous decision to cause an upset.
Modafferi said: "It feels incredibly relieving and satisfying to be back in the win column again. I hope my friends and family made some big money from this fight! I’ve been a little influenced by my coaches to embrace my dark side a bit more. I’m not naturally scary, so I tried to focus on that a little bit more to make sure people took me seriously.
"I did see that she got injured, so I wish her a speedy recovery. That’s just the way it goes sometimes, I have to take advantage of it and I’m just happy to stay in the top 10. I’m not afraid of anyone in the flyweight division, as long as they make weight. I have a pretty good record against people who have actually made weight. I hope the rules are tweaked a little bit to make sure people don’t miss weight so much.
"I want to keep winning and keep improving, team Syndicate is amazing and I can’t thank them enough."
Impressive Ferreira beats Bettis
GAD in Las Vegas: Diego Ferreira defeats Anthony Pettis via submission (Round 2, 1:46). Rear naked. That was most impressive from Ferreira. He is seen as a gathering force in the lightweight division and that was aggressive, smothering work.
There was a huge - actually deafening - cheer in the T-Mobile Arena a moment ago as Tom Brady, the New England Patriots quarterback, is shown on the big screen. Wonder if he can fight?
Tyson Fury is in the house
Yusuff win could be first of many for African fighters
Gareth A Davies: Sodiq Yusuff defeated Andre Fili via unanimous decision. The 2020s will be marked by the rise and rise of African fighters in the MMA.
Yusuff said: "I expected a rough fight coming into it. I thought if I landed well that I could get him out of there. He was durable, he’s tough, but I didn’t really expect anything less than that. He’s been here for a long time, so he’s not just going to crumble under the pressure. I wish it could have been a little more action-packed in the third round because I did want that fight of the night bonus, it would help my family out a lot. It’s ok though, we got the win, so we’ll build on this and move on to the next one.
"This is definitely the biggest win of my career, I think Fili is right up there close to the rankings, so this should put me close to the top 15 and then I’ll start climbing that ladder. I take one fight at a time, that’s how I’ve done it my whole career. The only thing I’ve ever been sure about is that I would end up in the UFC, everything outside of that is ‘figure it out when we get there’. I knew my talent and work ethic would get me here. At the end, I gave a shout out to Nigeria and said, “my people, I’m here too. My older brothers have already gotten their belts, God willing I’ll get there too one day.”
Pettis picks to win McGregor early
Heres @Showtimepettis up next in a very tough fight... heres what he predicts for #McGregorCerrone -- like me he favours McGregor early, Cowboy late.— Gareth A Davies (@GarethADaviesDT) January 19, 2020
I think if Ferreira doesnt apply pressure here on his 5 fight win streak, former 155 champ Pettis wins pic.twitter.com/iAKuXU27I6
The atmosphere is building...
My cageside seat here in Las Vegas— Gareth A Davies (@GarethADaviesDT) January 19, 2020
Ready to rock here with the main card at @ufc#ufc246
Sodiq Yusuff 145
Anthony Pettis 155
Maurice Green heavy
Holly Holm 135
McGregor 155 Second Rd TKO pic.twitter.com/7I4TXslpem
McGregor: I predict a KO
Good evening, everyone. Conor McGregor is in typically confident mood before his return to the Octagon tonight against Donald 'Cowboy' Cerrone, but said any blood spilled will not be "bad blood".
McGregor said: "I've had my back and forth with Donald throughout the years. It's hard not to respect Donald right now and at this stage. He has my respect and although there will be blood spilled on January 18, it will not be bad blood. And for the Mystic Mac prediction, it will be a KO."
Cerrone said he was relishing the bout at the T-Mobile Arena.
"I'm going five rounds with this dude and I cannot wait til Saturday night. This is the fight I wanted. Conor is one of the last of a dying breed of fighters and I can't wait for Saturday night," he said.