Baldomir defeated Unified Welterweight Champion Zab Judah on January 7, 2006 in a mandatory challenge for Judah’s title. The fight took place in Madison Square Garden, and with his pressure style and hard right hands Baldomir won a unanimous decision (115-113, 114-113 and 115-112). Baldomir was crowned World Champion, after 6 months of preparations in Los Angeles with Amílcar Brusa. After the fight, he said “This is a tribute to [Argentine boxing legend] Monzón” who had died eleven years earlier on January 8.

On July 22, 2006 Baldomir successfully defended his WBC Welterweight title and won the IBA welterweight title by defeating fan favorite Arturo Gatti by TKO in the 9th round by overpowering the faster, but naturally smaller Gatti. This fight helped convince some skeptics that Baldomir’s win over Judah was no fluke. Baldomir then expressed a desire to fight Floyd Mayweather Jr. to continue his unlikely rise in the welterweight division.

Baldomir would eventually get his chance against the pound-for-pound king, Floyd Mayweather Jr., on November 4, 2006 in Las Vegas for the WBC, The Ring and lineal welterweight titles. Said Baldomir of this challenge: “Mayweather is very good, but I can beat him. I’m going right at him. I’m going to keep attacking and not give him a chance to breathe or move. Mayweather has never fought anyone like me before.”