 On February 20, 1996, Castillo made his professional boxing debut in Miami, Florida with a first-round TKO win over Kerry Parks.In fact, four of Castillo's first five pro opponents didn’t make it out of the opening round, and with an aggressive style and south paw power; Elieser quickly became a fan favorite in his adopted home of South Florida.By his ninth fight, Castillo was already fighting for and winning professional titles as he demolished 85-fight veteran Bobby Crabtree in just two rounds to win the WBC Continental Americas title in 1996.