It had to happen, even though until relatively recently it seemed like it wouldn’t. Even Top Rank CEO and Pacquiao promoter Bob Arum, as late as last year, thought it might not happen, but on the evening of May 2 before a crowd of nearly 17,000 people at the MGM Grand Garden Arena and an inestimable worldwide pay-per-view audience, the two top pound-for-pound fighters of the modern era will tentatively touch gloves. Undisputed welterweight champion Floyd Mayweather Jr. will fight Manny Pacquiao in the first of what is sure to be several matchups, barring a career-ending injury on the part of either boxer.

The entire boxing world considers Mayweather vs. Pacquiao the fight of this century. While commentators and observers universally believe both fighters are past their prime, few if any lament the fight not happening five years ago when “Money” and “Pacman” were in peak form. The wait may have been worth it, building anticipation and allowing all other contenders to fall by the wayside in defeat at hands of Mayweather or Pacquiao. “It would have been nice and big five years ago, but nothing like this,” said Arum at the March 11 press conference at L.A.’s Nokia Center.

The rivalry isn’t just limited to the fighters. Arum has been critical of MGM Grand, drawing the ire of Mayweather Promotions CEO Leonard Ellerbe in the press in return. The fight pits popular Pacquiao trainer Freddie Roach (who has trained everyone from Oscar De La Hoya to MMA fighters BJ Penn and Tito Ortiz) against Mayweather’s father and uncle, former pro boxers Floyd Sr. and Roger Mayweather. Roach dropped all pretense of politeness at the press conference at the conclusion of his statement when he turned to Mayweather Jr. and said, “We’re fighting the best fighter in the world, and we’re going to kick his ass. I’m sorry, but good luck, Floyd.”

It may be the most polarizing pairing since Muhammad Ali and Joe Frazier. Mayweather is the Man in Full, focused and committed to victory, although the usually outspoken champion seemed emotionally affected at Nokia Center as he talked about the most important battle of his career so far. His past brashness has not been forgotten by Man of the People Pacquiao, who deflected Mayweather’s string of attempts to discredit him by suing him for defamation in 2012, agreeing to the Mayweather camp’s stringent demands and suggesting both fighters’ purses be donated to charity.

The outcome of the inaugural Mayweather-Pacquiao fight will come down to a clash of contrasting skill sets. Scientific-minded Mayweather has reach and height advantage, and a defense that has been nearly impenetrable to the fighters he’s defeated in his professional career. Southpaw Pacquiao, with two losses and 38 knockouts in 64 pro fights, has superhuman speed and can deliver an endless supply of devastating punches. Mike Tyson and Muhammad Ali give the edge to Pacquiao, while Shane Mosley, defeated by both as a pro welterweight, gives Mayweather the edge due to his reach advantage. Regardless of the outcome, Mayweather-Pacquiao II seems assured.

MGM Grand, 3 p.m. May 2. 800.745.3000 Ticketmaster