24 September 2021 – Singapore: ONE Championship™ (ONE) electrified the Singapore Indoor Stadium with ONE: REVOLUTION, which aired live on Friday, 24 September. The event featured a completely stacked card of mixed martial arts, Muay Thai, and kickboxing matches, headlined by three World Title bouts.

In the main event, #3-ranked lightweight Ok Rae Yoon stunned longtime titleholder Christian Lee to capture the ONE Lightweight World Championship.