The circus came to town and the double act who have been clowning around America en route to London by putting on a show of mutual belligerence flew on identical private jets across the Atlantic.
Mayweather spelled out the reality with crystal clarity: ‘It’s kill or be killed. Yield or don’t yield…’
Then he added, pointedly in reference to one of McGregor’s MMA defeats: ‘What I do know is that I don’t quit.’
Money Mayweather and Notorious McGregor packed out this final leg of the promotional tour for their mega-bucks fight on August 26.
The 11,000 free tickets to watch them go through their routine at Wembley Arena were snaffled while they were mid-air somewhere between Los Angeles, Toronto and New York.
For the fourth night running two fighters who are about to become hundreds of millions of dollars richer between them had the punters roaring in the aisles.
Many queued all afternoon to get a good position for the show of bombast, threats and stunts which will fill the T-Mobile Arena in Vegas and hoover up millions of pay-per-view TV buyers on both sides of the Atlantic.
Mayweather is never shy to admit that it’s all about the money. So he will go ahead with proving himself superior at boxing to McGregor, the biggest star of the UFC even though the Irish folk hero has brought some unsavoury racist undertones to their bellicose argument.
McGregor seemingly insulting Afro-American men and women, Mayweather says: ‘To get respect you must give respect. He disrespected black women, he calls black people monkeys. He spoke disrespectful to my daughter.
‘I don’t stoop to that level. He has just had a baby boy and I hope he enjoys his beautiful family. I have friends from all walks of life.
‘I don’t really know him. I just know he can fight and he’s tough and he’s an entertainer. I still respect him as a man. But to earn my respect as a fighter he has to prove it in the fight.’
Mayweather seems to subscribe to that when he says: ‘McGregor has brought back the vintage Mayweather. And we need more of the original Baby Boy Floyd in combat sports.
The crowds at these shows have been predominantly UFC fans and McGregor supporters.
Mayweather declined to go to McGregor’s home city of Dublin with London being hostile enough.
But he says: ‘No matter how many are rooting for me and how many rooting against me the only thing that matters is what happens between two men in the fight. As I said it’s kill or be killed.’