Petchdam Petchyindee Academy

In his first fight since losing the ONE Kickboxing Flyweight World Title, Petchdam will face Kohei "Momotaro" Kodera at ONE Championship: Fire & Fury on January 31, 2020. After a slow start in the first round, he would defeat Momotaro by majority decision.

In what would be his biggest test in ONE Championship, Petchdam Petchyindee Academy faced Algerian Elias Mahmoudi for the inaugural ONE Kickboxing Flyweight World Championship at ONE Championship: Warriors of Light. Despite a slow start to the fight, having to fight under kickboxing rules, Petchdam would slowly find his rhythm. An accidental low kick from Petchdam in the fifth and final round would render Mahmoudi unable to continue. Petchdam would win the title via technical decision. In his first title defense at ONE Championship: Dreams of Gold on August 16, 2019, Petchdam Petchyindee Academy would face Dutch-Moroccan kickboxer Ilias Ennahachi. Being overwhelmed by Ennahachi's punching combinations, Petchdam was knocked down in the second round. In the third round, a left hook from Ennahachi sent him down for a second time and Petchdam ultimately lost the fight and the title via 3rd-round knockout. This would also mark his first loss in ONE Championship.

Petchdam Petchyindee Academy made his ONE Super Series debut on July 18, 2018 at ONE Championship: Pursuit of Power, where he knocked out Australian Josh Tonna in the 2nd round. His next appearance on ONE Championship was in his home country of Thailand at ONE Championship: Kingdom of Heroes on October 6, 2018, where he scored a 1st-round knockout over Kenny Tse. Petchdam would continue his run of dominance in ONE Super Series in 2019 when he faced Masahide Kudo at ONE Championship: Call to Greatness on February 22. He knocked out Kudo in 35 seconds of the 2nd round.