Diaz started boxing at the age of twelve and had 205 amateur fights (191-14). He fought as an amateur for eleven years and was a member of the Cuban national team until he was 25.[1] Diaz fought the Félix Savón twice, and he reportedly scored two knockdowns in the fights, but Savon won both by decision.[citation needed]
On August 13, 2004, Diaz upset highly regarded and undefeated Cuban heavyweight prospect and former cruiserweight champion Juan Carlos Gomez with a vicious 1-round TKO. Still in 2004 he scored a victory over former title challenger Vaughn Bean.[citation needed]
However, his ascension was derailed on January 22, 2005, via a 5-round TKO loss to Nigerian power puncher Samuel Peter. He did not manage to score a win ever since, losing four out of his last six fights with two no contests. His last bout was in 2006 December when he was knocked out by former world champion Oliver McCall.[citation needed]
His current professional record stands at 13 wins (8 KOs) 5 losses and 2 no contests in 20 bouts.[citation needed]