Conor McGregor stops Donald Cerrone in first round at UFC 246

Conor McGregor spent the week leading up to his return to competition displaying a new calm and mature attitude.

Then he went out Saturday night and delivered a vintage McGregor performance in a 40-second knockout of Donald “Cowboy” Cerrone in the welterweight main event of UFC 246 at T-Mobile Arena.

It was McGregor’s first win since 2016 in his first fight since October 2018.

McGregor staggered Cerrone with a left head kick moments into the bout. He knocked him down with two left hands and landed a barrage of punches on the ground, but the fight was never in doubt after the kick.

“He wasn’t expecting that,” McGregor said of the head kick.

McGregor charged across the cage at the opening bell and clinched with Cerrone after missing with a left hand.

He landed four straight shoulder checks that appeared to catch Cerrone off guard.

After they separated, McGregor blocked a right kick and followed with the decisive left foot to the head.

McGregor landed 19 significant strikes in the 40 seconds and absorbed none, according to ESPN Stats & Info.

He was more concerned with making history as the first fighter in UFC history to record a knockout at featherweight, lightweight and welterweight.

“I made history tonight. I set another record,” said McGregor, the first fighter to simultaneously hold belts in two weight classes. Two others have done it since.

“I’m so happy. I’m very proud of that accomplishment. UFC can strip fighters and give other fighters make-believe belts, but they can’t give out knockout victories across multiple weight divisions. Etch my name in history one more time.”

It was the third consecutive knockout loss for Cerrone, who vowed to continue.

“I’ve never seen anything like that,” said Cerrone, 36. “He busted my nose, and it started bleeding, and I stepped back and he head-kicked me. I love this sport, and I’m going to keep fighting.”

McGregor opened up several intriguing options with the spectacular performance.

He could go back to lightweight and challenge for the title after Tony Ferguson challenges champion Khabib Nurmagomedov in April.

McGregor also could stay at welterweight and fight ultra-popular Jorge Masvidal. He has mentioned going back to boxing to fight Floyd Mayweather or Manny Pacquiao this year, possibly at Allegiant Stadium.

“I like this weight, and I feel good,” McGregor said of fighting at 170 pounds. “God willing, I came out of here unscathed and I’m in shape. I’m going to celebrate and talk to my family before getting back to the gym with my team.”

Pacquiao was definitely watching.

“THE NOTORIOUS!!!,” he tweeted immediately after the knockout.

McGregor had not fought since a lightweight title loss to Nurmagomedov in October 2018 at T-Mobile Arena. The fight was marred by an ugly postfight brawl inside and outside the cage.

It was a much different scene Saturday, as McGregor embraced an emotional Cerrone before dropping to his knees and taking in the roar of the capacity crowd.

The event did a live gate of $11,089,129, fourth-best in UFC history and second for an MMA event in Nevada behind McGregor’s fight against Nurmagomedov.

Contact Adam Hill at ahill@reviewjournal.com. Follow @AdamHillLVRJ on Twitter.