He came to Las Vegas and UFC 189 with the strength of a nation behind him, thousands of Irishmen coming together on the Strip for a weekend no one will soon forget. For new UFC interim featherweight champion Conor McGregor, Saturday night was either going to be a raucous party or the world's most raucous funeral.
There would be no middle ground.
Luckily for the very partisan crowd, a thunderous left hand made sure all the tears were joyful, sending opponent Chad Mendes turtling to the mat and ushering in a new era—or perhaps a new Eire.
Aging pop star Sinead O'Connor set the tone, with her version of the classic ballad "The Foggy Dew" reminding everyone from the Emerald Isle of the contest's stakes. McGregor, more than any other fighter in UFC history, wasn't fighting for himself alone; he represented the Irish, as he was propelled by their power but also burdened by their weight.
It's an old romance, that between the people and their amorous cavalier. Patriotism, pride and ancient ethnic enmity have long powered combat sports. In fact, British boxer Ricky Hatton had been in McGregor's shoes in the very same building—but his barbarous hordes and all their heraldries could do little to help him against Floyd Mayweather Jr.
But McGregor is no Hatton. And Mendes, despite sharing a nickname, is no Mayweather.
Whippet thin but healthy, McGregor emerged Saturday a far cry from the man who appeared the day before at the weigh-in meager, barefoot and wan. Confidence was his game, a swagger rooted in defiance, hate and scorn—a serpent in man's form.
Mendes, as many expected, provided the test that had to eventually come. With just two weeks to train, the former All-American remained a sleeping dragon with a ready shield. He landed early, with hard punches and easy takedowns. McGregor took it in stride, with his iron chin casting doubt into the wrestler's eyes and no doubt fear into his heart.
McGregor, it turned out, is susceptible to the takedown, a kryptonite that also plagued UFC legend Anderson Silva. His stance, legs spread impossibly far apart, makes him easy game for a powerful wrestler. But, like Silva, he was calm on his back, even in the face of serious firepower, throwing elbows of his own from the bottom and delivering a harsh penance whenever he eventually returned to his feet.
The best you could say for McGregor, through most of two rounds, was that he was a survivor, a tough guy who ate Mendes' best shots but couldn't defend his best shots—a flawed fighter who needed some time back at the drawing board.
"Make no mistake, Mendes was winning the fight," Fox Sports analyst Kenny Florian said after the bout. "He was doing unbelievable in the fight."
But though he was winning on all three judges' scorecards, Mendes looked for a finish early, trying to secure a guillotine choke rather than secure his position when McGregor attempted to escape to his feet late in the second round.
Whether it was his short training camp, McGregor's vicious body kicks or both, Mendes looked spent. With three long rounds looming, perhaps the dream of early victory seemed preferable to the grind of dealing with McGregor's omnipotence for 15 more minutes.
It was a fatal mistake. A reinvigorated McGregor creased the right side of Mendes' face—"the soft part" as he likes to say—with a left hand that dropped Money to the mat. McGregor's is an unmatched dedication to the kill, to ensuring victory with a fighter's best tools: his fists.
"I'm overwhelmed," McGregor said after the fight. "When I stopped my opponent, I jumped up on the cage I was so excited. I'm blown away. I put a lot of work into this. It came out of me after the fight. The buildup to this, the up and down, it was a lot of work. I'm just blown away."
The MGM Grand Garden Arena exploded in pure joy; it emitted a festive clarion of triumph. But the boisterous din must eventually abate, and McGregor must eventually face an even more daunting task—the one who originally brought him to Las Vegas in the first place.
Longtime champion Jose Aldo looms.
"Jose Aldo is a little more nervous right now," UFC light heavyweight champion Daniel Cormier said on Fox Sports 1 after the fight. "I'm picking McGregor in any stand-up fight he gets now, and all wrestlers are scared of him now."
When the fight finally occurs, it will be bigger than ever. A huge horde of 16,019 fans crowded the arena for this bout, drawing an American MMA record gate of $7.2 million. After months of buildup, a world tour and McGregor's emergence as the true, rightful top contender, the fight might actually end up being exactly what UFC president Dana White promised it would be: the biggest fight in UFC history.
The key to it all is McGregor. The trash talk and his motor-mouth delivered him to this stage. But it is incredible power and his power of will that will keep him here. Yes, he's beatable. Mendes revealed cracks in his armor, but it will require 25 minutes of perfection and discipline to take advantage of them.
When McGregor hits people, they stay hit. It's a rare force that cures many ills and guarantees he's always in the fight, even when his opponent appears to be winning. This combination of vulnerability and fearsome ability is the golden ticket to box-office riches.
None of this will come as a surprise to his legions of fans. But even his critics can no longer deny the obvious: McGregor is for real.
Jonathan Snowden covers combat sports for Bleacher Report.