 In 1980 Oguma landed a shot at WBC and Lineal Flyweight Champion Chan-Hee Park and KO'd Park in the 9th round to capture the titles.He defended the titles twice the same year, including a split decision over Park, and his annual performance was named Ring magazine Comeback of the Year for 1980.In 1981 Oguma defended the titles successfully again against Park, but lost the belts in his following bout by KO to Antonio Avelar.