Years of debate and months of hype have come to a head as Manny Pacquiao and Floyd Mayweather slug it out in Las Vegas for the most eagerly anticipated boxing match in recent memory.

Saturday's long-awaited bout, which has been more than five years in the making, has transcended the traditional boxing scene, catapulted the sport back into the public consciousness and promises to rewrite the record books as the most lucrative fight of all time.

"Sin City" was buzzing ahead of the welterweight world title showdown and the money men were rubbing their hands: total revenue for the bout could reach an eye-watering $400 million, fuelled by as many as three million pay-per-view purchases.

The breathtaking figures - touted as high as a possible $180 million payday for the unbeaten American and an estimated $120 million bonanza for Filipino icon Pacquiao - have intensified the spotlight on a fight between two of the most successful boxers of their generation.

Al Jazeera's Andy Gallacher, reporting from Las Vegas, said the atmosphere in the city was "electric" as hundreds of thousands of people had swarmed there just to be close to the fight.

"It's been building up and counting down and now the streets of Las Vegas are completely packed," Gallacher said.

In the Philippines, Al Jazeera's Jamela Alindogan, reporting from General Santos, said an "unofficial holiday" had been declared in the country of 100 million, with streets packed with thousands of the boxer's supporters waiting to watch the match.

Boxer Manny Pacquiao, of the Philippines, poses for fans at a rally in Las Vegas [The Associated Press]

As a taster for the main event at the MGM Grand Garden Arena, a crowd of 11,500 turned out for Friday's weigh-in, as Pacquiao and Mayweather went nose-to-nose.

The few tickets that did go on sale for the bout itself were reportedly snapped up in one minute, with A-listers and high-rollers making up the vast majority of a 16,800 sell-out crowd, making the fight more akin to a night at the Oscars than two men attempting to pound the other to the canvas.

With just hours to go, dozens of tickets were still available on the resale website StubHub, ranging in price from $2,690 to $37,442 apiece.

Las Vegas tourism officials said occupancy for the city's 150,000 hotel rooms would approach 100 percent.

Casinos were advertising red-carpet events hosted by hip-hop stars such as Puff Daddy and Snoop Dogg and pop star Justin Bieber - a Mayweather fan and friend.

Clash of styles

And then there was the small issue of the fight itself, which even if it doesn't measure up to Mayweather's claim of the "biggest fight in boxing history," is an intriguing clash of styles between men of contrasting personalities.

Pacquiao, 36, a two-term politician with a music and film career, credits the grace of God for lifting him from poverty in his youth and later guiding him away from a life of excess that his ring success made possible.

As a child he slept in a cardboard box and sold bread for $2 a day to help his family survive. 

"Pacman," who undoubtedly had the crowd on his side at the weigh-in, will go into the ring with all of the Philippines in his corner.

The brash Mayweather, known as "Money" and "Pretty Boy Floyd", touts his status as a money-making machine and comes from a troubled past that includes jail time for one of a string of domestic violence incidents.

Mayweather, 47-0 with 26 knockouts, is a 2-1 favourite to add Pacquiao's World Boxing Organisation world title to his own World Boxing Association and World Boxing Council belts.

Public opinion is with Pacquiao but some boxing experts say Mayweather will triumph, most likely by a 12-round decision.

Mayweather, 38, is a supremely skilled boxer and potentially devastating counter-puncher, famed for his ability to hit without being hit.

Pacquiao 'the underdog'

Pacquiao, who weighed in a pound lighter, will be in the unenviable position of the smaller fighter, taking more of the risks.

The aggressive southpaw, who owns a record of 57-5-2 with 38 knockouts, says he is content in his underdog role.

A winner of world titles in an unprecedented eight weight divisions, Pacquiao noted that he's beaten plenty of bigger foes, among them Oscar De La Hoya in 2008.

"No one thought I could beat Oscar, and I was the underdog then," said Pacquiao, who moved up 12 pounds in weight to batter the "Golden Boy" in a fight that sent him into retirement. "Maybe it's good for me."

Once each had stepped off the scale on Friday, Mayweather and Pacquiao came eye-to-eye for a stare down - just their third face-to-face meeting since the bout was announced in February.

"I've dedicated myself to the sport of boxing for more than 20 years," Mayweather said. "I'm ready."

Source: Al Jazeera And AFP