Manny Pacquiao's top fights

33m - Boxing
Making The Rounds: Pacquiao's most important wins

Ahead of the May 2 superfight between Floyd Mayweather and Manny Pacquiao, Brian Campbell breaks down the five most important wins in the career of the PacMan.

Trying to pin down and define the top five victories of Manny Pacquiao's legendary career can be a difficult task because of how many chapters and turns there have been as he daringly rose in weight.

But despite how many moments jump out when taking a glance at Pacquiao's resume, one thing is certain: He has never entered a fight that has meant so much to his legacy as his May 2 superfight against Floyd Mayweather in their long-awaited welterweight unification bout at the MGM Grand in Las Vegas.

For both Pacquiao (57-5-2, 38 KOs) and Mayweather (47-0, 26 KOs), a victory offers the chance at undisputed supremacy in not only their division or the sport as a whole from a pound-for-pound sense, but the winner probably will be remembered as the best of their era.

But before we find out what happens on May 2, let's look back at a countdown of Pacquiao's five most important victories to date:

5. April 12, 2014 -- UD12 Timothy Bradley Jr. (rematch) -- MGM Grand Garden Arena, Las Vegas

With apologies to Pacquiao's pair of 2006 stoppages against Erik Morales or his 2001 destruction of Lehlo Ledwaba, PacMan's win over Bradley in their rematch makes the cut for more reasons than one might realize. On the surface, it put to bed any lingering doubt from Bradley's all-time controversial decision win in their first fight from 2012. But looking deeper, it solidified the belief that Pacquiao had fully recovered from his one-punch knockout loss to Juan Manuel Marquez. With the unbeaten Bradley entering the fight as the No. 3 pound-for-pound fighter in the world and fresh off a victory over Marquez, the win helped Pacquiao, at 35, re-establish himself as a truly elite fighter. Without the credibility of this victory, the bout with Mayweather wouldn't be nearly as big as it is right now.

4. March 15, 2008 -- SD12 Juan Manuel Marquez (rematch) -- Mandalay Bay, Las Vegas

If the fourth installment of the Pacquiao-Marquez rivalry from 2012 stands out as the most exciting from an action standpoint, their 2008 rematch might still be their best actual fight. In the final bout for both at junior lightweight, this was a meeting between two all-time great fighters at the peak of their lower-weight primes. For Pacquiao, it was a showcase of just how far he had come under trainer Freddie Roach after evolving into a complete fighter. And while the scorecards from their first three fights are still debated to this day, Pacquiao avenged the draw from their first bout four years earlier, using the tight victory as a springboard for his meteoric rise in weight that would follow.

3. Dec. 6, 2008 -- TKO8 Oscar De La Hoya -- MGM Grand Garden Arena, Las Vegas

After only one fight at lightweight, Pacquiao moved up two weight classes for this superfight billed as the "Dream Match." The result, however, was nothing more than a nightmare for the 35-year-old De La Hoya. Pacquiao's speed and relentless combination punching simply overwhelmed the heavily favored "Golden Boy," who left too much of himself on the scales. The impact of the win was monumental for Pacquiao as De La Hoya passed the torch of true pay-per-view viability to PacMan in the same way he had done a year earlier in his loss to Mayweather. The fight generated 1.25 million PPV buys, beginning a stretch of nine straight bouts in which Pacquiao generated at least 700,000 buys, with six eclipsing the 1 million mark.

2. Nov. 15, 2003 -- TKO11 Marco Antonio Barrera (first fight) -- Alamodome, San Antonio

The raw and exciting Pacquiao emerged from nowhere in 2001 to upset Ledwaba on two weeks' notice and claim a junior featherweight title in his U.S. debut. But it wasn't until his 2003 showdown with the red-hot Barrera -- who entered the bout on the heels of victories over the likes of Naseem Hamed and Erik Morales -- that we found out how good he really was. Pacquiao was simply a storm too explosive for Barrera to handle on this night, with his corner intervening late to rescue him from the damage. The victory did more to open up the doors to the kind of big-money fights that would follow than any other in Pacquiao's career, legitimizing him as a star in the making.

1. Nov. 14, 2009 -- TKO12 Miguel Cotto -- MGM Grand Garden Arena, Las Vegas

After six years of watching Pacquiao as a full-fledged welterweight, it's easy to forget how ridiculous a notion the thought once was. How would PacMan deal with the size and strength of an elite welterweight in his prime? Was the victory over De La Hoya the previous year merely a mirage because of Oscar's age and weight drain? These were the kinds of questions facing Pacquiao in this welterweight title bout, fought at a catchweight of 145 pounds. But he didn't just pass the test against Cotto, he rewrote the questions. Pacquiao stood toe to toe while enduring heavy damage throughout the first four rounds, which teased the notion that an all-time great fight might be brewing. But those ideas faded quickly over the next eight rounds as Pacquiao's speed and awkwardness slowly dismantled Cotto until referee Kenny Bayless mercifully waved it off in the final round. HBO's Larry Merchant said it best following the fight: "We thought Manny Pacquiao was great. He's better than we thought."