Celebs weigh in on Pacquiao-Mayweather battle

Justin Bieber supports Mayweather while Arnold Swarzenegger believes Pacquiao will triumph.

Floyd Mayweather Jr and Manny Pacquiao face off during their official weigh-in at MGM Grand Garden Arena in Las Vegas, Nevada. Picture: Getty Images/AFP.

JOHANNESBURG - Celebrities have chosen their sides in the Floyd Mayweather Jr vs. Manny Pacquiao fight, billed as 'The Battle for Greatness' or 'The Fight of the Century' which will take place on 3 May at the MGM Grand Garden Arena in Las Vegas, Nevada.

Backing Pacquiao are Mark Wahlberg, Keanu Reeves, Sylvester Stallone, Arnold Swarzenegger, OJ Simpson's lawyer Robert Shapiro and Micky Rourke.

And celebrities in Mayweather's corner are Jay-Z and Beyonce, Snoop Dogg, LeBron James, 50 Cent, David Hasselhof, Li'l Kim, Jamie Foxx, Mariah Carey and Justin Bieber.

Bieber is confirmed to walk Mayweather down to the ring, carrying some of his title belts with him.

What had been a subdued buildup to the most anticipated fight in decades exploded to life at the weigh-in this morning when Pacquiao and then Mayweather entered the MGM Grand Garden Arena to thumping hip-hop music and deafening cheers from a seething crowd of 11,500, some of whom had waited three hours for a glimpse of the two boxers.

Their meeting is expected to be the biggest grossing prize fight of all-time.

On 20 February, 2015, Mayweather confirmed on social media that the fight had indeed been signed by himself as Pacquiao already had signed the contract of the fight previously and the contract itself was with Mayweather on that day.

At the weigh-in, Pacquiao came in at 65 kilograms while Mayweather weighed a kilogram heavier at 66.

The fighters have been compared to previous legendary boxers, including Lennox Lewis and Evander Holyfield.

WATCH: The weigh-in.

Pacquiao could walk away with $113 million while Mayweather stands to win $210 million.

"I have dedicated myself to the sport of boxing for the last 20 years and I am ready," declared Mayweather over a roar of boos and cheers.

Asked for a prediction about the fight, the 38-year-old American said, "I can't really say but I am ready to fight. It's an unbelievable turnout. I'm glad all the fans came out to here to support Manny and me."

Normally free and open to the public, the weigh-in broke from tradition, charging $10 to watch Mayweather and Pacquiao step onto the scales in a move designed to maintain crowd control.

All money raised through ticket sales went to charity, but many of the tickets found their way onto the resale market with some commanding $500.

A smiling Pacquiao, dressed in a bright red track suit, waved and raised his fists into the air as he slowly made his way to the stage, playfully interacting with the crowd.

In stark contrast, Mayweather was serious and focused, rarely looking up from under the brim of his 'Money Team' baseball cap to reveal a cheeky smirk.

Once the business of the official weigh-in was complete, the two welterweights moved to the front of the stage for the traditional stare down, the smaller Pacquiao looking up at Mayweather with a challenging smile while the stone-faced American stared straight-ahead unmoved.

"I have been fighting bigger guys like (Antonio) Margarito and (Oscar) De La Hoya," said the Filipino southpaw.

"It doesn't matter to me. I feel tomorrow that the Lord is always with me and gives me strength.

"I know it's a great, great responsibility for me to give enjoyment to the fans.

"Tomorrow the fans deserve to have a great fight."

Mayweather is the World Boxing Council champion, and he is also the World Boxing Association champion, while Pacquiao is the World Boxing Organisation champion.

In a fight of the two biggest names in boxing, who do you think is going to win?

Here's what the Twittersphere had to say about the fight...

Crime plunges & wars stop in Philippines when Manny Pacquiao fights. "That's how big it is." http://t.co/n8RaSi8sTE pic.twitter.com/1Y4TUMcIOD

I want @MannyPacquiao to knock @FloydMayweather out so hard that Floyd actually learns to read!

RT for Manny Pacquiao

FAV for Mayweather


#PusongPacquiao pic.twitter.com/SiEdFGedS7

100% backing @FloydMayweather tonight!! He's gonna kill it!! πŸ™ŒπŸ‘ŠπŸ‘Š

On Mayweather beating women @Scienceofsport: perhaps you saw this. From this article: http://t.co/nnNyHXdC28 pic.twitter.com/xCFHNwXLb8"

Tonight is the Night

@FloydMayweather @MannyPacquiao

#TeamPacman pic.twitter.com/xUsjVLFX1H