McGregor banking on knockout blow

Mixed martial arts star Conor McGregor vowed to knock out boxer Floyd Mayweather on Friday as a horde of Irish fans descended on Las Vegas for the trash-talking rivals' cross-combat super-fight.

McGregor, 29, will carry a substantial weight advantage into Saturday's 12-round boxing contest after a raucous weigh-in that saw him face-off with Mayweather for the final time before fight-night.

With waves of green-shirted fans in a crowd of around 6,000 roaring their support for the Irish superstar, McGregor tipped the scales at 153 pounds, well inside the 154-pound limit.

Former welterweight champion Mayweather, 40, who has emerged from a two-year retirement to take on MMA star McGregor, weighed in at 149.5 pounds.

The naturally bigger McGregor -- who screamed into Mayweather's face as the two men went nose-to-nose -- said he expects to enter the ring at closer to 170 pounds.

McGregor, who has never fought in a professional boxing contest, is a massive underdog for a fight, which is expected to beamed live to around 200 countries and territories across the globe.

But the former apprentice plumber from Dublin, who was unemployed four years ago, defiantly predicted he was ready to spring a monumental upset on the skilful Mayweather, one of the finest boxers in history who boasts a perfect 49-0 record.

"That's the worst shape I've ever seen him," McGregor said of Mayweather. "I'm going to breeze through him, trust me on that."

A nonplussed Mayweather shrugged off his weight disadvantage and once again vowed to stop McGregor inside the distance.

"Weight doesn't win fights, fighting wins fights," Mayweather said. "It won't go the distance."

Saturday's bout has appalled boxing traditionalists, who have rubbished the event as a meaningless, money-grabbing, mismatch which owes more to the pantomime traditions of WWE wrestling than the noble art.

Boxing pundits, coaches and fighters have lined up to dismiss McGregor's hopes of succeeding where 49 others in Mayweather's 21-year career have failed.

"Would a ping-pong player have a chance of scoring a point against Roger Federer?" was the withering verdict of veteran trainer Teddy Atlas. "It's going to be like walking through a really bad neighbourhood late at night. McGregor's going to get mugged."

Others however have sounded a note of caution, citing potential safety risks to McGregor given the chasm of experience between the Irishman and Mayweather.

British former light-welterweight world champion Amir Khan expressed fears  McGregor could be seriously injured.

ZLATAN'S VERDICT

"Here you have a guy that has made a career out of many years and that is Mayweather. And then you have the other guy that has made a career in a short time, but he made himself a big name. Me as a huge fan of the MMA, I see this fight. I don't know. It can go both ways. Either what people predict that Mayweather will win easy, which I don't believe. I see Conor with his confidence. He will win. Because he believes in himself so much."

MONEY MACHINE

Although the exact figures that the fight will generate depend on a number of variables such as pay-per-view sales and ticket sales among others, the Nevada State Athletic Commission confirmed on Friday night that the minimum purse for each fighter.

Mayweather is guaranteed 100 million dollars, 80 million less than what he was paid for his fight against Manny Pacquiao. However, at the moment Mayweather is projected to earn upwards of 200 million dollars should sales go smoothly.

McGregor meanwhile will make a minimum of 30 million, nearly 10 times what he made his previous high salary. That figure could rise to 75 million.

If PPV revenue stays in line with the Mayweather-Pacquiao bout, the purse is likely to be worth 300 million, with total revenues at 700 million.

Although the split between the boxers will not be revealed, industry insiders speculate that it is either 75-25 or 70-30 in Mayweather's favour. That means a $300 purse would net him 225 million, and leave McGregor with 75 million.