The welterweight rivals finally collide at the MGM Grand in the early hours of Sunday morning, repairing boxing’s credibility after a succession of false dawns dating back to 2010.
Lawsuits, hostility between rival promoters and broadcasters and Mayweather’s blood testing demands prevented the two finest fighters of their generation from clashing until the breakthrough in negotiations came in February.
The answer to years of barroom debate will be delivered when the richest bout in history unfolds in the Nevada desert with unbeaten Mayweather knowing the delay in facing Pacquiao has doubled the value of the fight to an estimated €449 million.
“Everything takes time, it’s all about timing. I’m glad that we had patience and didn’t rush. The time is now, this is the right time for this fight,” Mayweather said.
“This fight is not good versus evil, it’s about one fighter who is at the top fighting another fighter who is at the top. It’s about giving excitement.
“We don’t know how this fight is going to play out, but I believe in my skills. I believe I am going to be victorious.”
Staging the biggest sporting event of the year, for which a mere 500 of the 16,500 arena seats were made available for general sale, is only half the battle as an increasingly-rare crossover moment offers boxing the platform to recapture hearts and minds.
A September rematch is inevitable if the event excites, but a poor spectacle or the occurrence of the type of controversy that happens all too frequently will invite renewed scorn just as publicity is at its greatest.
Mayweather is a defensive genius, admired for his technical brilliance rather than warrior spirit, and it is Pacquiao’s all-action style that will cause the heart to race.
The Filipino southpaw, who is two years younger at 36 but has engaged in 17 more fights, would be the popular winner with the bragging and ostentatious Mayweather happy to play the role of villain as he nears a fight that will determine his legacy.
“I believe in self-preservation. Me first, then everyone else. But me first. Nobody is going to love Floyd Mayweather like Floyd Mayweather,” he said.
“I’m not focused on all the festivities going on. I’m just focussing on being the best I can be, doing what I’m supposed to do.
“I come out and speak loud and do flamboyant things, talking about money. But that doesn’t mean that I hate anyone, its all about entertainment. People want to be entertained.”
Records already held by Mayweather for pay-per-view buys, gate receipts and closed circuit television revenue will tumble, setting a level of expectation that two outstanding but fading fighters will struggle to meet.
Mayweather’s precious 47-0 unbeaten record, just two short of Rocky Marciano’s hallowed mark, is expected to face its greatest challenge yet against an opponent who was forced to rebuild after a dramatic knockout by Juan Manuel Marquez in 2012.
Subsequent victories over Brandon Rios, Tim Bradley and Chris Algieri reignited interest in the superfight, but Pacquiao’s fall to Marquez — one of five shared foes — supports Mayweather’s claim he is reckless.
Pacquiao’s instincts are to attack, throwing rapid combinations and wearing down opponents with his energy, but pressure tactics have yet to succeed against the reigning pound for pound king.
“Everybody’s game-plan is to come forward and throw lots of punches. They think it will work, but it hasn’t worked in 19 years and 47 fights,” Mayweather said.
“My reach is 72 inches. It’s all about keeping fighters at bay and I feel like I’m more calculated.
“I truly believe I’m the smarter fighter. He would be a better fighter if he wasn’t so reckless — it’s a gift and a curse to him.
“He has won a lot of fights by being reckless, but you can also be reckless and get knocked out.
“And getting knocked out in a harsh way can affect you in the long run, when your career is over.
“I know I can fight. I can really dish it out because I don’t really take too much. If I was a reckless fighter, my career would have been extremely short.”
Mayweather, who starts as a strong favourite with a points victory the most widely tipped result, is as happy playing the role of victim as villain and few tears will be shed should he slump to a first defeat.
“The bar is always set high for Floyd Mayweather, it’s always set a little different to everyone else,” he said. “If we turn the table and we look at the situation whereby if I’d been knocked out by Marquez, this fight would never have happened.
“Sometimes in fights I shut guys out, but they call it a spilt decision or a majority decision. My hands are always tied behind my back, the standards are always set higher for me. I’m damned if I do and damned if I don’t. But only God can judge me.”