Ryan Garcia needed less than four minutes to blow away Conor Benn before turning his sights on the rest of the welterweight division.

The 28-year-old American demolished Benn inside two rounds on Saturday night to retain his World Boxing Council championship at 147lb, dropping the British challenger with a concussive right hand before the referee stepped in moments later at T-Mobile Arena in Las Vegas. The sensational finish ignited the mostly pro-Garcia crowd of 18,855 on Mexican Independence Day weekend. Then, with Teófimo López taunting him from ringside and threatening to storm the ring, Garcia made it clear he was ready to take on all comers.

“We got to clear this [division] out,” said Garcia (26-2, 21 KOs), who was making the first defense of the welterweight title he won by flooring and outpointing Mario Barrios at the same arena in February.

Benn (25-2, 14 KOs), who had promised “tenacity, ferocity, spite” throughout an acrimonious build-up and vowed to pressure Garcia from the first bell, made good on that pledge. He set a frenetic pace in the opening frame, bolting from his corner and dragging Garcia into heavy exchanges. Benn scored well to the body and caught the champion with a shot to the back of the head that went unpunished, while Garcia repeatedly threw his signature left hook in an ominous statement of intent.

The decisive sequence came early in the second when Benn was attempting to close the distance. Garcia caught him flush on the chin with a right hand he never appeared to see coming, sending him crashing to the canvas in a heap. Benn made it back to his feet but was plainly hurt, prompting the champion to close in immediately and unload with both hands until third man Thomas Taylor intervened at the 1min 25sec mark.

“The first round I was just saying, ‘Just protect yourself. He’s going to get crazy. Just really worry about just watching what he’s doing, download, download, download,’” Garcia said. “Then I started hitting him. I was like, ‘Oh wow, I’m already timing him.’ And then the second round I said, ‘I’m just going to stand my ground a little bit. I’m going to get my respect real quick.’

“And then when I did, I ended up knocking him out.”

The defeat thwarted Benn’s bid to follow in the footsteps of his father, Nigel, who held the WBC super-middleweight title more than three decades ago. The 29-year-old from Essex had not fought at the welterweight limit in four and a half years after campaigning as high as middleweight and described the process of returning to 147lb as going through the “pits of hell”. He nevertheless came in at 146lb at Friday’s weigh-in, his lightest in seven years.

Garcia disputed any suggestion that the stoppage was premature. “They could have stopped it when he was on the ground,” he said. “He was out of it. I looked at him in the eyes and he wasn’t even there. If it would’ve kept going, you would’ve seen a man unconscious on the floor. It’s the ref’s job to stop the fight when it needs to be done, to protect the fighter.”

The fight was co-promoted by Zuffa Boxing, the fledgling venture of UFC supremo Dana White which poached Benn in April after his entire 10-year career with Eddie Hearn’s Matchroom. Garcia remains under contract with Oscar De La Hoya’s Golden Boy, which spent months sparring with Zuffa over the matchup before the sides came to a deal.

Saturday’s spectacle also represented the latest step in the rehabilitation of two fighters whose careers had recently been threatened by doping controversies. Garcia tested positive for the banned anabolic agent ostarine around his April 2024 victory over Devin Haney. The result was overturned to a no-contest and Garcia was suspended for one year, with his team blaming contaminated supplements.

Benn’s ordeal was more complicated. Two positive tests for clomifene emerged before his proposed 2022 fight with Chris Eubank Jr, keeping him from fighting in Britain for two years. Benn maintained his innocence throughout and was ultimately cleared by the National Anti-Doping Panel.

Yet there they were on Saturday, reportedly earning around $15m apiece in one of the biggest fights of the year. Garcia leaves Las Vegas with his belt, his reputation burnished and no shortage of lucrative options.

Indeed, the televised post-fight interview quickly descended into the sort of chaos that has followed Garcia, one of boxing’s first Gen-Z superstars, throughout his tumultuous career in the spotlight. He spotted López at ringside and summoned the WBA titleholder toward the ring, shouting: “Unified time. Where you at, Teo?”

When López responded, Garcia escalated matters. “You want to get crazy, we going to get crazy,” he said. “I’ll beat your ass right now.”

Then came a challenge to Haney, the WBO champion and another interested observer at ringside given the unfinished business surrounding their drug-tainted first encounter. “Hopefully we get to beat Devin Haney’s ass again for undisputed,” Garcia said. “Fuck the Haneys!”

Nor are those Garcia’s only options. Four-division world champion Shakur Stevenson, campaigning one division below at 140lb for now, was also in the arena on Saturday as a member of the Paramount+ commentary team and expressed interest in a fight with Garcia, who remains one of the sport’s most marketable American stars.

Later, Garcia made his immediate preference clear. “I want to unify against Teófimo,” he said. “I think that’s the move. It’s a huge fight and Teó’s an entertaining dude and it’s going to be a hell of a buildup and he’s a good fighter too, so let’s run it.”

Where Benn goes from here is less clear. He had already suggested this would be his final appearance at welterweight after describing the arduous weight cut to 147lb. Still not yet 30 and a proven attraction in Britain, he is unlikely to lack decent options at a more natural weight. He was transported to hospital after the fight for observation without speaking to reportersm, but struck a gracious note on social media. “Not my night, no excuses,” he wrote, calling Garcia “a great champion”.