Mayweather had retired in 2015 after beating Andre Berto to move to a record-equalling 49-0 alongside Rocky Marciano, but could not resist the chance to take the record for himself against a debutant and earn a healthy purse along the way. 

McGregor had become a global superstar, having just become the first-ever simultaneous double champion in the history of the UFC -  knocking out Eddie Alvarez. 

The pair began to exchange barbs in 2017 when McGregor called out Mayweather to fight, claiming it would be the biggest fight in the history of either sport. 

UFC president Dana White initially dismissed the fight as McGregor was still contracted with the UFC, but quickly backpedalled when he realised the magnitude of the contest and the opportunity to skyrocket the profile of his organisation. 

Talks continued through the year with Mayweather telling McGregor to “stop blowing smoke up everyone’s a**” and to “sign the paper.” 

The official fight announcement came on June 14, and a feisty press tour followed, where both men did their duty in promoting the fight to within an inch of its life. 

Their hard work paid dividends, and many thought that the bout would eclipse the PPV numbers of Mayweather vs Pacquiao in 2015, which was the most financially successful fight of all time, registering 4.6 million buys. 

While it did not quite reach those heights, it nestled comfortably in second position with 4.3 million buys, nearly doubling the next in line, Mayweather vs Canelo Alvarez. Here's how it played out...

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McGregor impresses early 

The UFC champion set his intentions early, jumping on Mayweather and unloading well-varied, point-scoring combinations. 

His unorthodox southpaw style presented an interesting puzzle for the former multi-division champion to unlock, but fundamental issues like a high chin and relaxed hands would be early signs of things to come. 

The Irishman put the crowd on their feet when he landed an impressive uppercut on Mayweather that showed signs of the American’s age and slowing reactions. 

All three judges gave the first round to McGregor, who took the round on volume rather than efficiency. 

The same continued through the first quarter of the fight, with McGregor showing impressive footwork, switching between southpaw and orthodox to create different angles of attack, landing with the jab and rear hand more than we had seen some legitimate world title contenders in the past. 

But McGregor’s early flashes of brilliance were little more than that - style over substance. He did take the second and third rounds on one of the judges’ scorecards, but this would signal the end of an impressive start. 

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Mayweather asserts himself

After taking the early rounds to presumably download information on McGregor’s style and habits, Mayweather began to invest in the body – knowing his opponent’s youth and explosiveness were the only things keeping him in the contest. 

Jabs and backhands to the body made up a significant portion of Mayweather’s work. He remained consistent despite McGregor’s rudimentary understanding of the rules, which saw him take Mayweather’s back and attempt to land hammerfists to the back of his head on multiple occasions. 

Mayweather punctuated the beginning of his takeover with a signature pull counter that knocked the snot out of McGregor – literally – demonstrating his technical mastery. 

He walked the UFC double champ down with a high guard and took advantage of his ability to fight on the inside, where McGregor looked uncomfortable. 

The showboating and flashy footwork had all but disappeared by the fifth round as the Irishman circled the ring with his mouth open and his hands down. A lack of experience pacing himself over 12 rounds and the educated body work from Mayweather was taking its toll.

It became obvious that McGregor did not have much more to give in the fight and began to take a worrying number of clean shots, simply unable to return fire with enough power to deter the advancing Mayweather. 

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The finish

Mayweather had all but abandoned his attempts to outbox the Irishman and simply marched forward, throwing simple straight shots that knocked an off-balance and exhausted McGregor around the ring. 

‘Money’ advanced with a wry grin on his face, knowing the end was nigh; it was just a case of whether or not McGregor would be on his feet. But the UFC superstar valiantly stayed up, absorbing crushing shots from Mayweather until the referee had seen enough and stopped the contest in the 10th round. The Irishman accepted the result like a champion and immediately embraced his foe, recognising true brilliance. 

McGregor did not win a single round on the scorecards after the third, but that does not take away from what is arguably the most impressive crossover boxing performance we have seen to date, making the fight competitive from the outset against one of boxing's all-time greats. 

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