On July 15, 2003, he won the USBA and NABA super middleweight titles after beating Richard Grant by unanimous decision. He defended all three of his belts against Donnell Wiggins by TKO 8. He later fought Syd Vanderpool for the vacant IBF super middleweight title on October 2, 2004, winning by TKO in 8 rounds. He defended it against Omar Sheika, Rubin Williams, former champion Robin Reid, and Scott Pemberton.
On March 5, 2006, Lacy lost his title to Joe Calzaghe. Despite being a favorite going into the fight, Lacy lost by a unanimous points decision and was knocked down in the twelfth round. The fight was extremely one sided with scores of 119-105, 119-107 and 119-107.
On August 15, 2009, Lacy suffered a 10th round technical knockout to Roy Jones Jr. Sixteen months following the loss to Jones Jr., Lacy returned to his hometown of St. Petersburg, Florida to face journeymen Dhafir Smith. Smith defeated Lacy by a unanimous decision.
Lacy is now reportedly in talks to fight mixed martial arts champion Nick Diaz in a professional boxing match.
Explosive left hook
Major World Titles
IBO Super Middleweight (2005)
IBF Super Middleweight (2004-06)
Member of 2000 U.S. Olympic Team
Amateur record: 209-12