 He won the vacant OPBF Super Flyweight Title in 1999, and defended it twice.His first world title match was against South Korean fighter In-Joo Cho in 2000, whom he beat by unanimous decision over 12 rounds, becoming the first North Korean to win a boxing world title.He defended his WBC and lineal super-flyweight titles eight times before suffering a stunning first-round knockout loss to Katsushige Kawashima in 2004.