While it was not the first crossover bout, it is undoubtedly the biggest and will remain so for many years to come.
On the four-year anniversary of the clash, this is the story of how Mayweather and McGregor created an event that transcended the sport of boxing and dazzled sports fans the world over.
In 2017, Mayweather and McGregor were undoubtedly the two biggest combat sports stars in the world.
Despite retiring in 2015 following his victory over Andre Berto, Mayweather had remained a vocal figure in and around the world of professional boxing.
His stature at the time was rivalled perhaps only by heavyweight star Anthony Joshua, former rival Manny Pacquiao, and Mexican sensation Canelo Alvarez; even then, and even in retirement, Mayweather was in a league of his own.
While there were always rumours of ‘one more fight’, there never seemed an opponent tailor-made for Floyd.
Then, along came Conor McGregor.
If Mayweather was the prize-fighting king sailing off into the sunset, then McGregor was the rightful heir to the throne.
After arriving in the UFC just two years before Mayweather’s retirement, the Irishman put the promotion’s featherweight and lightweight divisions on notice.
He smashed through the likes of Jose Aldo, Eddie Alvarez, and Chad Mendes, and became the UFC’s poster boy in record time thanks to his exceptional fighting skill and brilliance on the microphone.
Following his sensational knockout of lightweight champion Alvarez in 2016, there were whispers that Mayweather wanted his piece of the McGregor pie.
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These whispers became a lot louder when the legendary boxer took to Instagram and shared an unofficial fight poster for a bout between the pair, telling fans he was very interested in a fight against the Irishman.
While UFC president Dana White did his best to hold onto his biggest star and prevent talks from beginning, once McGregor caught wind of the enormous purse he was set to earn, the bout was as good as confirmed.
A year on from Mayweather’s first Instagram post, and after months of intense back-and-forth negotiations, contracts were signed, and the fighters took to Twitter to share the news.
The Biggest Fight in Combat Sports History was on.
The build-up to Mayweather vs McGregor was about as you’d expect.
Across five press conferences, both men traded countless, personal insults, with boxing and MMA fans getting involved in the rivalry as well.
Mayweather took aim at McGregor’s previous losses and labelled the Irishman “Mr. Tap Out”, “Dana’s b***h” and, most strangely, “a microwaved meal”.
McGregor fired numerous shots of his own and was, by far, the more vocal of the two men at each press event.
During the events, he mocked Mayweather’s inability to read, claimed Mayweather had failed to knock anyone out “in about 30 years” and got 15,000 rowdy Canadian fans to scream “f***k the Mayweather’s” in unison.
Alongside his rivalry with Mayweather, McGregor became embroiled in a bizarre feud with another retired boxer, Paulie Malignaggi.
After being enlisted as one of McGregor’s sparring partners, Malignaggi stormed out of the Irishman’s camp when footage was released of the MMA star supposedly sending the two-weight world champion to the canvas.
In the weeks that followed, Malignaggi blasted McGregor to virtually every reporter that would listen and appeared desperate to face the Irishman next.
While a bout between the pair would never materialise, Malignaggi would go on to face McGregor’s teammate Artem Lobov in a bare-knuckle boxing match. He was defeated by the 13-15 MMA fighter via decision.
Mayweather’s clash with McGregor was always going to be huge, but few would have expected the bout to be as big as it was.
By the time the opening bell rang at the MGM Grand Hotel on August 26, 2017, over $1billion had been staked on the fight around the world, with a record £60million traded on Betfair alone.
Initially, the Irishman was priced as a heavy 7/1 underdog but swiftly fell to 3/1 with MMA fans confident that his one-shot knockout power would prove decisive in the fight.
In contrast, Mayweather was priced by the bookies between 1/12 and 2/9, with his odds fluctuating throughout fight week.
Reportedly, Mayweather, an avid sports bettor himself, attempted to place a $400k (£290k) bet on himself to win the contest under 9.5 rounds.
The bet was declined due to concerns over the legality of a fighter betting on anything other than a win, leaving the undefeated boxer “p****d”.
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Countless fighters, celebrities and analysts jumped in with their own prediction’s days out from fight night, with virtually every boxer, MMA fighter, and celebrity backing Mayweather.
Heavyweight icon Mike Tyson said, “Conor’s not skilled enough to box with Floyd”, while former champion Deontay Wilder stated, “It’s like Floyd always say, ‘It’s like robbing a bank because it’s easy money.’
Ricky Hatton and Andre Berto, both former opponents of Mayweather, also backed the undefeated boxer, with Hatton saying, “It’s two different sports…Conor’s not going to hit him.”
Anthony Joshua, Kamaru Usman, Jose Aldo, and the legendary James Toney all rubbished McGregor’s chances as well. AJ said, “It’s probably going to be a landslide”, while Aldo claimed, “There is no way McGregor can defeat Mayweather.”
The stage was set.
14,623 fans filed into the MGM Grand to see a retired boxer take on an MMA fighter with virtually no boxing experience.
On the undercard, Gervonta Davis and Badou Jack produced sensational knockouts of Francisco Fonseca and Nathan Cleverly respectively.
Then it was time.
McGregor entered first, with an Irish flag draped over his shoulders and Sinead O’Connor’s rendition of the Foggy Dew blaring in the background. He grinned at the cameras, raised his fists to the crowd, and looked ready for war.
Mayweather was second, bizarrely dressed in a black balaclava, black and gold gown, and a black cap with ‘TBE’ on the front.
He arrived in the ring with Meek Mill’s track Ima Boss filling the arena. Like McGregor, he was prepared for a battle.
Jimmy Lennon Jr carried out the formalities, announcing both men’s records and achievements. The pair then came face to face, touched gloves, and grinned at one another. Then they were off.
Despite many rubbishing McGregor’s chances, the Irishman had success from the opening bell and was ahead on one judge’s scorecard for the first few rounds.
Sure, Mayweather was never in any real trouble and looked totally comfortable standing opposite McGregor, but the Irishman had his moments.
However, as has been McGregor’s main issue throughout his combat sports career, he quickly began to tire as the fight went on.
From the fourth round, it was one-way traffic.
The more punches the Irishman threw, the more Mayweather dodged, weaved, and blocked, and every time a punch was avoided, McGregor looked a little more tired.
As the energy was sapped from the Irishman’s body, Mayweather landed some venomous shots of his own.
He fired his piston-like right hand constantly, and landed virtually every time he wanted.
Mayweather continued upping the pace throughout the next few rounds and landed more and more blows as the fight went on. His coaches told him to “go for the kill”, and he did just that.
By the tenth-round, McGregor was on his knees.
27 minutes with one of the best boxers of all-time had left him shattered, and ripe for the taking.
Mayweather backed him to the corner and landed a vicious flurry, wobbling McGregor. The Irishman slumped down and held on for dear life.
The American pushed him away and landed yet another stinging right hand, which again wobbled McGregor.
The Irishman continued retreating, but the punches kept coming.
Another right, then a left hand, and another right. McGregor again attempted to hold on, but he was fighting a lost cause.
Two more unanswered blows from Mayweather, and referee Robert Byrd had no choice but to stop the contest.
Mayweather had won via tenth-round knockout. His first victory via stoppage in over half a decade.
Following the bout, both men gave their thoughts on the result and while McGregor felt slightly hard done by with the result, Mayweather told reporters “I will always be remembered as a winner.”
McGregor told ESPN, “I think I smoked him in the early rounds. I think I was pretty handily whopping him in the early rounds. Then he changed his style.
“I wasn’t prepared for that. I hadn’t anticipated that, you know. He was composed in there. I wasted my shots. It was just a composure issue.
“I wasn’t hurt. I wasn’t wobbled once. I give him a hat off. Fair play to him. He’s a composed man, you can give him nothing but respect.”
Mayweather shared his own delight following the contest during the post-fight press conference.
“The whole game plan was to let him go out and shoot heavy shots from the beginning. Take him down the stretch and do what we do best.
“I guaranteed this fight wouldn’t go the distance. I told you I was going for the knockout.
“After 21 years in the sport of boxing, I had some great fights and I had some boring fights, but I will always be remembered as a winner.”
Following the contest, it was revealed that Mayweather had earned a whopping £200m from the bout while McGregor pocketed just shy of £100m.
Mayweather would retire from professional boxing for good and has only competed in low-risk exhibition bouts since.
In contrast, McGregor returned to MMA and has won just one fight since, losing to Khabib Nurmagomedov and Dustin Poirier twice.
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