By Joseph Santoliquito

LAS VEGAS, NV (CBS) — Floyd Mayweather Jr. and Manny Pacquiao are dissimilar in so many ways. Mayweather began his career as a junior lightweight, Pacquiao as a flyweight. One is viewed as an ingrate, the other beloved by the boxing community. One is humble, the other excessive.

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And if it has to be pointed out to you which one is which, you don’t know boxing.

Mayweather has not lost a fight since August 2, 1996, or in 6,846 days (on May 2, 2015, which translates into 18 years, eight months, and 29 days), when Bulgaria’s Serafim Todorov decisioned him in the Olympic featherweight semifinals.

Pacquiao’s latest setback came a little more recent.

The two, however, do have five common opponents — Oscar De La Hoya, Shane Mosley, Ricky Hatton, Miguel Cotto and Juan Manuel Marquez.

Here is a breakdown of the five, what happened and what it could possibly mean when Mayweather faces off against “Pac-Man” on May 2 in Las Vegas:

5. Oscar De La Hoya

Pacquiao TKO 8 De La Hoya, Dec. 6, 2008: “Pac-Man” closed out the “The Golden Boy.” A deflated De La Hoya came down for the fight, and he had nothing left.

Mayweather W 12 De La Hoya, May 5, 2007: De La Hoya came the closest to beating Mayweather. De La Hoya was 2-2 in his last four fights entering the ring. Mayweather still fought a better version of De La Hoya.

4. Ricky Hatton

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Pacquiao KO 2 Hatton, May 2, 2009: Pacquiao made the point he could stop Hatton eight rounds before Mayweather did.

Mayweather TKO 10 Hatton, Dec. 8, 2007: Mayweather handed Hatton his first career pro loss in devastating fashion, then proceeded to take two years off.

3. Shane Mosley

Pacquiao W 12 Mosley, May 7, 2011: Mosley was 2-2-1 in his last five fights leading up to Pacquiao at welterweight. This came a year after Mosley lost to Mayweather. By then, a year’s time diminished Mosley’s reflexes.

Mayweather W 12 Mosely, May 1, 2010: This is the closest Mayweather came to being stopped—and it was a brief stunning blow that buckled Mayweather’s knees in the second. Afterward, Money went on to win every second of every round that followed.

2. Miguel Cotto

Pacquiao TKO 12 Cotto, Nov. 14, 2009: Cotto was a prime 147-pounder. Pacquiao moved up to face him. Size was no difference. Pacquiao bounced Cotto in the third and fourth rounds before finishing him.

Mayweather W 12 Cotto, May 5, 2012: Many thought it was closer than the 117-111 (2) and 118-110 scores. Mayweather was coming up to 154 pounds to meet Cotto, who borrowed De La Hoya’s template to beat Mayweather. That’s to rough him up, get him against the ropes and pound away at any body part available. It still didn’t work, though Mayweather’s face was bruised more than normal.

1. Juan Manuel Marquez
Pacquiao D 12 Marquez, May 8, 2004:
Pacquiao W 12 Marquez, March 15, 2008:
Pacquiao W 12 Marquez, Dec. 12, 2011:
Marquez KO 6 Pacquiao, Dec. 8, 2012: Mayweather doesn’t have the power Marquez carried in his last fight against Pacquiao. But the relative ease with which Mayweather dispensed of Marquez doesn’t bode well for Pac-Man.

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Mayweather W 12 Marquez, Sept. 19, 2009: Mayweather came off nearly a two-year absence to handle Marquez easily. Marquez was left lunging and chasing after Mayweather, possibly like Pacquiao will be forced to do if Mayweather builds an early lead. If there is a fight that could resemble what “Money”-“Pac-Man” will look like, it could be Mayweather’s domination over Marquez.