The pair pointed into each other's faces after making their way onto the Budweiser Stage in a much more heated staredown than at the previous day's press conference in Los Angeles.
Calvillo was one of the sport's top prospects as an amateur, as she went 5-1 with three finishes from 2012 to 2014. McGregor said. "Dance for me, boy!".
Referencing the 40-year-old's history of domestic abuse accusations and promotion of adult establishments, Kavanagh sent a truly bone chilling warning, referring McGregor as a dark animal from the boxer's worst nightmares.
"Fans all around the world demanded this fight", said Mayweather, expecting to earn more than $100 million for the August fight. "Of course, he's going to say how good he is". You can buy the fight for about $90 on Showtime pay-per-view.
"Yeah he was right", Mayweather said.
"F-k Showtime, too! You little weasel. If you believe in yourself like you say you believe in yourself, bet your own fight check, you [expletive]".
And McGregor responded: "No f****** problem, send the contract, kid, it's done".
CONOR McGREGOR and Floyd Mayweather kept the hype train rolling as their four-day press tour landed in Toronto last night and, unsurprisingly, things got out of control quickly. Racism still exists but you know, I try to take something negative and turn it into something positive. "You may not think boy means anything, but you've never heard boy from a racist bigot cr***er-ass cr***er from down south". And I want to continue to watch you grow.
"I'd like to sleep on it, but it took me by surprise", he said.
By that logic if the press conferences are being scored, round one went to Mayweather, who came unglued while attacking McGregor on every front during his tirade across the stage. Make no mistake about it: Mayweather vs. McGregor is about the money, it's always been about the money, and that's just fine.
McGregor played to the crowd and posed for the cameras. It concludes Friday at the SSE Arena at Wembley in London.