by Mark Mayer | Manny Pacquiao, considered by many the best pound-for-pound fighter in boxing with the retirement of Floyd Mayweather Jr., goes for this fifth world title tonight at Mandalay Bay in his first bout as a lightweight. Pacquiao previously won championships at 112, 122, 126 and 130 pounds. Now at 135, he faces the unheralded David Diaz, who has just one loss in 36 fights (34-1-1).
Pacquiao is a prohibitive -500 favorite at Caesars Palace and moved up to -550 at MGM MIRAGE properties early Saturday. Its the first fight for Pacquiao since winning a close split decision against Juan Manuel Marquez back on March 15. Diaz won the WBC lightweight title in 2006 with a 10th round knockout of Jose Armando Santa Cruz. Both fighters have beaten Erik Morales, while Diaz has two wins over Zab Judah in the 1996 Olympic trials.
Pacquiao (46-3-2, 34 knockouts) has the speed advantage in the matchup, while Diaz is known more for his toughness than knockout ability (17 KOs). Diaz solidified his hold of the title with the victory over Morales, a narrow but unanimous decision. He tried to rise to the 140-pound division, but was stopped by Kendall Holt.
In the undercard, featherweight titleholder Steven Luevano is a 9-2 favorite to retain his belt against Mario Santiago. The champion only has 15 knockouts in 36 fights. Santiago has 14 on his 19-1 record.