It’s finally here.

More than five years ago, Floyd Mayweather and Manny Pacquiao were on a collision course for their first career meeting. But the undefeated Mayweather’s drug test demands, the split of the purse, and messy lawsuit filed by Pacquiao derailed any chance the two would square off to decide the best fighter of their generation.

Mayweather (47-0, 26 KOs) faced accusations that he was ducking the Filipino superstar who was viewed as the only opponent capable of tagging and defeating the ever elusive five-division champion.

Now the two welterweights will step inside the MGM Grand Arena ring in Las Vegas Saturday night to settle the score.

Due to his perfect record and legendary defense and counterpunching abilities, Mayweather is the favorite to win a super-fight that's expected to blow away all previous pay-per-view buy and gate records. Retailing for either $89 for standard definition or $99 for high definition, more than three million PPV buys totaling $300 million in revenue are expected, with Mayweather and Pacquiao divvying up a $200 million purse at a 60-40 split.

Despite owning the distinction as the highest-earning athlete in the world, Mayweather said his choice to at-long-last tangle with Pacquiao came down to one thing.

"Money," he said. "My kids. I'm not going to lie to you. Of course, everything plays a major key. I love the fans, I want to give them excitement, I love them."

A victory for Pacquaio, which some experts have predicted, would catapult him into another stratosphere of boxing lore, and wipe away the stain of his embarrassing knockout loss to rival Juan Manuel Marquez more than two years ago.

The 38-year-old Mayweather, as well as Pacquiao, have hinted at retirement after the HBO-Showtime co-sponsored bout. Mayweather could join only a handful of other fighters to go out on top with a blemish-free record, while Pacquaio might find it difficult to lure another worthy opponent into the ring should he pull off the upset.

The role of underdog is one Pacquiao, 36, is more than familiar with. His trainer, Freddie Roach, credited Pacquiao’s struggles as a child to his rise to the top of the boxing world.

“He lived on the street,” Roach said to reporters, “where he bought doughnuts at a doughnut store and then sold each one for a nickel more to survive. He slept in a cardboard box. He fought his way through all this, turned pro at 14, and look at the man he is today.”

With his father and trainer, Floyd Sr., in his corner Mayweather looks to cap a career few in the sport can match. Counting his record-breaking victory over Oscar De La Hoya in 2007, the 10th round technical knockout of Ricky Hatton later that year, and the unanimous decisions over Shane Mosley, Miguel Cotto, and Marquez, a convincing win over Pacquiao figures to place Mayweather alongside the likes of “Sugar” Ray Leonard, Marvin Hagler, and even heavyweights like Muhammad Ali.

Scheduled Start Time: The bout is scheduled to begin at 11 p.m. ET

Actual Start Time: Depending on how the undercard plays out, the bout could get going a little after 11 p.m., but it’s more likely Mayweather and Pacquiao will drag out the start to after 11:30 p.m.

Expect both to enter the ring and commence the “Fight of the Century” between 11:30 and 11:45 p.m. to make sure everyone in arena is at their seats and that the West coast has enough time to settle in.