“IT’S my life. I love MMA. MMA is what the world should be,” said Alex Santana, a huge fan of mixed martial arts (MMA)—a fast-growing combat sport that uses techniques from boxing, wrestling, judo, kickboxing and Brazilian jiu-jitsu. He admires its honour code. He coaches it to children and goes to as many bouts run by Ultimate Fighting Championship (UFC), the world’s largest MMA promotion company, as possible. On November 12th he had flown to New York from Los Angeles, without buying a ticket, in the hopes of witnessing UFC 205—the first MMA event ever held in New York state, which legalised the sport earlier this year. A “nosebleed” seat all the way up in Madison Square Garden’s (MSG) highest and least-coveted deck cost him $1,500 on eBay, 15 times the face value of the cheapest tickets for the event. He ventured out to Queens to pick it up from a seller whom he described as the “most cracked-out dude I’ve ever seen”. Mr Santana was far from alone in his pilgrimage. Close to the octagon, celebrities like Madonna and Hugh Jackman turned out for the big card. Further afield, devotees of the sport flocked to the Big Apple from all across America and all over the world for the event. Judging by the accents and patriotic outfits at the venue, Irish fans seemed particularly plentiful. Enda Sexton, originally from Ireland, flew in all the way from Australia, and was still hunting for a ticket a few hours before the bouts were to begin. Why come all the way? “It’s a big deal”, he explained.

UFC 205 was a big deal to UFC too. Just a few short years ago, MMA was widely seen as a fringe sport with limited appeal and questionable morality: John McCain, a Republican senator, once called it “human cockfighting”. But since 2001, when Zuffa, a promotion company, purchased UFC for $2m, it has cleaned up its act and its image, largely thanks to judicious regulations like the prohibition of eye-gouging. Today, matches can be bloody and competitors often limp away with broken bones, but the injuries tend to be minor.

As a result, UFC seems to have pinpointed a sweet spot between unbridled barbarism and social acceptability, and has now reached a scale that would have been unimaginable at the turn of the millennium. It has held a total of 373 events in 125 cities. Although it does not reveal its revenues, Fox Sports is paying it $100m over seven years for broadcast rights. And the demographics of its fan base suggest it has further room to grow: the company says its fans are younger than those of any other American professional sports league, with a median age of 38.6. This claim is bolstered by its strong social-media presence: UFC currently boasts 25m followers on Facebook, 11m on Twitter and a further 9m on Instagram. Some 130,000 enthusiasts belong to UFC gyms.

With the wind at their backs, UFC’s shareholders decided to cash in earlier this year, selling the firm at a $4bn valuation to WME-IMG, a talent agency. It is now recruiting celebrity investors to raise its profile: last month it announced that the actors Ben Affleck, Mark Wahlberg and Sylvester Stallone, and the star athletes Serena and Venus Williams and Tom Brady had taken stakes in the company. Conan O’Brien and Jimmy Kimmel, a pair of widely-viewed chat-show hosts, have also invested and intend to feature UFC fighters on their programmes.

In UFC’s long quest to go mainstream, its inability to operate in New York, America’s biggest media stage, was an ever-growing irritant. Although the bouts it held just across the river in New Jersey sold out, they failed to capture the city’s attention. In 1997 New York banned MMA for its excessive brutality. Since then, the sport has become legal in every other state. But despite two decades of aggressive lobbying, Sheldon Silver, the longtime Democratic Speaker of the state Assembly, consistently blocked efforts to authorise it. Safety concerns aside, gossips in Albany suspected UFC was being held hostage in a proxy war over an unrelated issue: Mr Silver is a staunch union ally, and the owners of Zuffa also ran a casino in Las Vegas that did not have a contract with Nevada’s formidable culinary-workers union.

Mr Silver’s long hold over lawmaking in New York came to an end in February 2015, when he stepped down amidst an investigation of allegations of corruption. (He was convicted this May, but is free on bail pending his appeal against the ruling.) That opened the door to legalisation. Once UFC agreed to insure each fighter for $1m in case of a traumatic brain injury, Andrew Cuomo, the governor, signed a bill reversing the ban. He says he expects the sport to generate $137m in annual economic activity for New York—half of which will be spent upstate—and to generate $5.4m a year in state and local taxes.

As long as UFC was excluded from Madison Square Garden (MSG), it was never able to shake its image fully as a shady and not-quite-kosher pastime. Now that the ban has been lifted, the firm hopes that its perceived newfound respectability will reverberate far beyond the Big Apple. Although Las Vegas, which hosts many MMA bouts, may be the fight capital of the world, MSG is its mecca: it hosted Rocky Marciano’s defeat of Joe Louis in 1951, the “Fight of the Century” between Muhammad Ali and Joe Frazier two decades later and the heavyweight title bout between Evander Holyfield and Lennox Lewis, which brought in the arena’s highest-ever gate of $13.5m. Now, with traditional boxing (particularly the heavyweight variety) an increasingly niche sport (though still a fabulously lucrative one), UFC is poised to fill the void. UFC 205 shattered the Holyfield-Lewis record with gate revenue of $17.7m, instantly making this upstart sport the king of the venue that calls itself the “world’s most famous arena”.

The final hurdle for UFC is likely to be developing marketable stars who can transcend its base audience. So far, only Ronda Rousey, the “world’s toughest woman”, has had any breakout success, and she is still far from a household name. For the time being, UFC is pinning its hopes on Conor McGregor (pictured), nicknamed “The Notorious”. The Dublin-born star is a study in contrasts: a struggling plumber’s assistant just a few years ago, he is now known for a dandy dress sense (he sported a white Gucci mink coat to the pre-fight press conference) as well as for his brutality in the octagon. His swagger was on full display at MSG: after knocking down his opponent, Eddie Alvarez, three times in the first round alone, he taunted Mr Alvarez by putting his hands behind his back and daring him to attack, a brash show of arrogance. It took Mr McGregor just two rounds to knock out Mr Alvarez, making him the first MMA fighter to hold two title belts simultaneously. “I’m always looking to make history every day,” he said after the bout, channeling the bravado of the late Muhammad Ali. “[I’m] unprecedented.”

Fans at the arena were eating it up. Iain Freckleton, a 26-year old plasterer with a bushy red beard, travelled from Scotland for “the chance to come here and to be a part of history. The card is unreal,” he said. “There will never be another first time in New York.” Those at home appear to have been equally enthusiastic: pay-per-view sales are expected to eclipse the sport’s previous high of 1.65m. Nonetheless, UFC still has a ways to go before it dislodges the National Football League from the top of ESPN’s SportsCenter broadcast. It will take far more nights as successful as last Saturday for the sport to achieve its ambitions.