A little over two months after the fight was confirmed, Mayweather and McGregor touched gloves at Las Vegas's T-Mobile Arena.
Hype collided with reality as boxing legend Floyd Mayweather defeated mixed martial arts superstar Conor McGregor in a battle of combat sport kings tipped to be the richest fight in history.
A little over two months after the fight was confirmed in June, Mayweather and McGregor touched gloves at Las Vegas's T-Mobile Arena in a 10-round boxing contest which was beamed to more than 200 countries and territories.
Fight promoters have breathlessly talked about the bout surpassing the $600 million (508 million euros) generated by Mayweather's 2015 fight with Manny Pacquiao, insisting that interest was off chart.
"This is the biggest event that has ever happened in combat sports," said Dana White, the chief executive of MMA's Ultimate Fighting Championship.
"This fight will reach over a billion homes worldwide."
Ringside seats were offered on secondary ticket markets for an eye-watering $100,250 apiece before Thursday, even though some 1,700 seats in the 20,000-capacity venue remained unsold.
Millions of fans across the United States meanwhile shelled out $99.95 to watch the fight on pay-per-view television, the most important economic engine of the spectacle.
The sense of anticipation endured despite an unrelenting chorus of disparagement across the boxing world.
Farce. Freakshow. Circus. Mismatch. Rip-off. Bad for boxing.
It was impossible to follow the build-up to the fight without being made aware of the near-universal tide of derision.
A cursory glance at the tale of the tape explains the cynicism.
Mayweather, 40, is one of the most skilled boxers of his generation, a master of ringcraft who retired in 2015 after a glittering 21-year career with a perfect 49-0 record.
McGregor, a two-time world champion in UFC, has never boxed professionally and has looked awkward and ungainly during training camp sparring sessions.
He has demonstrated punching power in the UFC, but has never faced an opponent as elusive as Mayweather.
Anything other than a convincing Mayweather win would have been regarded as a surprise; a McGregor victory a monumental upset.
Yet the millions who parted with their cash to watch the fight in the arena or on television do not appear to be bothered by the possibility that they may be taken for an expensive ride.
Stephen Espinoza, the head of cable network Showtime Sports which soled the fight on pay-per-view in the US, said many tuned in on the off-chance of witnessing "something incredible."
"We did some focus group testing, and the casual fans were absolutely adamant," Espinoza said. "Their response almost universally was 'We don't care if it's a mismatch. We don't care if it's non-competitive -- if there's a .01 chance that something incredible could happen, we need to watch it.'
"And that's why they're going to watch it."
The two men at the centre of the action will be laughing all the way to the bank.
Pay-per-view targets seemed to be met, Mayweather could earn as much as $200 million, pushing his career earnings towards $1 billion.
McGregor, who four years ago was living off unemployment benefit in Dublin before his emergence as a star of MMA, could pocket $100 million.
A gaudy "Money Belt" was also won, comprising 3,360 diamonds, 600 sapphires, 300 emeralds mounted in 1.5 kilos of solid gold and set in alligator leather.
Both fighters engaged in a global publicity tour to drum up interest in the fight last month that was marked by a series of lurid verbal exchanges, ranging from expletives and homophobic slurs to allegations of racism.
Yet a final press conference between the two fighters on Wednesday saw something close to an outbreak of civility, with both men refraining from the trash-talking in a strangely subdued showdown.
Note: This artcicle was written before the fight but has been modified to fit the aftermath.
Floyd Mayweather outclassed Conor McGregor with a 10th-round stoppage to win their money-spinning superfight and clinch his 50th straight victory.