[1] Chua qualified for the men's 100 m breaststroke at the 2004 Summer Olympics in Athens, by achieving a FINA B-standard entry time of 1:04.93 from the Hong Kong Long Course Championships, three weeks before the Games were scheduled to begin.

[3][4] Despite his eligibility from FINA, Chua had been battling with the Philippine Amateur Swimming Association (PASA) for failing to inform officials and not granting a permission to compete for the qualifying tournament.

[1] On the first day of the Games, Chua challenged seven other swimmers in heat two, including three-time Olympians Jean Luc Razakarivony of Madagascar and Yevgeny Petrashov of Kyrgyzstan.

[5][6][7] At the 2005 Southeast Asian Games in Manila, Chua collected two bronze medals in the 100 m breaststroke (1:04.35) and 400 m medley relay (3:52.70), as a member of the host nation team.

[8] Shortly after the SEA Games, Chua retired from his 12-year swimming career, when he made a final decision to finish his engineering course at the University of the Philippines Diliman in Quezon City.