Ok started his professional MMA career in 2014 and mainly fought in East Asia, particularly Wu Lin Feng.
[4] Ok faced defending ONE Lightweight World Champion Christian Lee at ONE Championship: Revolution on September 24, 2021.
[6][7] Due to the controversial nature of the decision, it was reviewed by the ONE Competition Committee which ultimately upheld the result.
[10] He lost the bout after being dropped by Lee in the second round and being finished on the ground with knees.
[12][13] Ok faced Alibeg Rasulov for the interim ONE Lightweight World Championship on July 6, 2024, at ONE Fight Night 23.