Las Vegas, NV (My Sportsbook) - Defending champion Miguel Cotto tipped the scales at 145 pounds -- his lightest weight in more than three years -- one night ahead of his WBO welterweight title defense against Manny Pacquiao in the year's most anticipated pay-per-view bout at the MGM Grand in Las Vegas.

A winner in 34 of 35 fights since turning pro in 2001, Cotto agreed to come in two pounds below the weight division's traditional limit in order to secure the big-money bout with Pacquiao, who holds the IBO title at 140 pounds and is generally considered the world's top pound-for-pound fighter.

Pacquiao weighed 144 pounds, heavier than he's been for any of 54 bouts in a 14-year pro career.

A 29-year-old Puerto Rican, Cotto is former 140-pound champion who subsequently held the WBA's welterweight title before a controversial 11-round TKO loss to Antonio Margarito in July 2008.

Margarito was suspended six months later after commission inspectors found illegal substances in his hand wraps prior to a bout with Shane Mosley.

Cotto was a champion again one bout later, defeating Michael Jennings for the vacant WBO title at Madison Square Garden on February 21. He's defended once since, overcoming a bloody cut to top Joshua Clottey by a razor-thin split decision at MSG on June 13.

He weighed 147 for both the Jennings and Clottey bouts.

"We had a great training camp, which is the reason why I wanted to take our team to Tampa. I am facing a great fighter in Pacquiao," Cotto said. "He has great hand speed and a big heart. It will be a battle.

"I began boxing when I was a little boy, just 11 years old. I always dreamed of fighting for the world championship. I have fought in world title fights, won championships, but this fight is very special. I want to tell all of my fans that I am ready to fight. We have a great game plan and we will win."

Pacquiao, a former world title claimant at 112, 122, 130 and 135 pounds, weighed 142 pounds for a ninth-round stoppage of Oscar De La Hoya last December, a result that led to De La Hoya's retirement and propelled Pacquiao to the sport's consensus No. 1 spot.

He's fought once since, winning the IBO junior welterweight bout with a vicious one-punch stoppage of Ricky Hatton in round two of their scheduled 12- rounder at the MGM Grand on May 2.

"Cotto's size and power need to be respected, but I will leverage his size against him," Pacquiao said. "We have numerous plans to do this depending on the style of fight he presents on Saturday night. We are prepared. As important as it is to have advantages, knowing how to use them is even more crucial."

Now 30 years old and unbeaten since a decision loss to Erik Morales in 2005, the Filipino is 49-3-2 overall with 37 knockouts.

The undercard will include a WBC 154-pound title bout between champion Daniel Santos of Puerto Rico and unbeaten American Yuri Foreman.

Also featured is a 10-round bout involving Julio Cesar Chavez Jr., and a separate match with Alfonso Gomez, who was Arturo Gatti's final opponent in 2007 and lost a title challenge against Cotto in 2008.

Lyle Fitzsimmons is an award-winning 21-year sports journalist, a full voting member of the Boxing Writers Association of America and a frequent contributor to sports radio talk shows throughout the U.S. E-mail him at fitzbitz@msn.com, follow him at twitter.com/fitzbitz and read more at fitzbitzonfights.wordpress.com.