In November 2013, he managed to win 8–5 in the final against Poland Sebastian Batkowski [de] to become Junior World 9-ball Champion.

Later that year, he reached the semi-finals of the 2019 WPA World Nine-ball Championship, losing to eventual champion Fedor Gorst.

Chung, a former world ten-ball champion overcame an early 5–2 deficit and shattered a 12–12 tie, claiming five of the final six racks to snatch the title worth $30,000(P1.6 million) while Feliciano settled for the runner-up finish and $15,000 pot (P823,755).

I'm also grateful to the Sharks Billiard League for setting the stage and giving us the chance to compete with great opponents and for providing a very comfortable and world-class arena for us," said Ko.

Trailing 3–6 against Fedor Gorst, he won ten consecutive racks to win the biggest title of his career.