Conor McGregor promised to knock-out Floyd Mayweather inside of four rounds when the two meet inside a boxing ring on August 26.
Speaking in front of 20,000 fans at the Staples Centre in Los Angeles, the two-weight UFC Champion and Mayweather were on the first step of a four city tour to promote their bout.
The two fighters will go head-to-head in Las Vegas at the end of August and despite facing an opponent who has never tasted defeat in 49 fights, McGregor was in a typically confident and cocky mood.
The event itself suffered from production and sound problems but when the two fighters finally took the stage, sparks began to fly.
McGregor entered first, soaking up the cheers and applause of a partisan crowd with Mayweather coming on stage to a chorus of boos.
As the fighters faced off, McGregor attempted to goad and taunt his opponent but Mayweather looked on in bemusement.
The Dubliner was up front with his prediction for the bout and said: "I’m going to knock him out inside four rounds, mark my words.
"I’m a young confident happy man who has worked very hard for this. I am just up here embracing this.
"As far as the fight, he will be unconscious inside four rounds. The movement, the power, the ferociousness, he’s not experienced this.
"He's fought people who have shied away from him. I don’t fear him, I don’t fear this limited set of fighting," he added, referencing the fact that they meet under boxing rules rather than MMA.
"This is a limited set of rules that makes this half a fight, a quarter of a fight, so this isn’t a true fight. If this was a true fight it wouldn’t even take one round.
"As these rules, all these restrictions, it doesn’t faze me, it amuses me. The gloves, they have to be 10 ounce, we’re at 154lbs, I think he’s fought at 154lbs maybe once."
Mayweather watched McGregor’s animated speech passively, not appearing to be fazed by his opponents taunts, but he didn’t take long to fire back when it was his turn.
"21 is the number and they say why is 21 the number? Because that’s how long I’ve been kicking ass," the veteran 40-year-old said.
"You light them up and I’m going to knock them down like bowling pins and on August 26, I’m going to knock this b**** out too.
McGregor couldn’t resist responding to that, hitting back with; "He hasn’t knocked anybody out in about 20 years."
Mayweather did show a measure of grace however, thanking his opponent for the bout and the huge pay-day that will be coming to both fighters.
"I want to say thank to Conor McGregor, I want to thank you and your team. I’ve got to thank Dana White, because it takes two warriors to bring an event like this together and the two biggest names in combat sports did this.
"I didn’t do this by myself, this man played a major part in this fight. But August 26, that’s your ass," he told McGregor.
"I’m an old man. I’m not even the same man I was 20 years ago, I’m not the same fighter I was 10 years ago, I’m not the same fight I was five years ago, I’m not the same fighter I was two years ago, but I got enough to beat you.
"I guarantee you're going out on your face or your back."
