Career
In May 2007, Son first competed in the World Taekwondo Championships in Beijing, China at the age of 19, but lost to Algimiro Mejias of Venezuela in the bantamweight (-62 kg) first round. On July 22, 2009, Son was knocked out by Park Hyung-Jin in Round 2 of the featherweight (-68 kg) final match at the 2009 President"s Cup in Ulsan, South of Korea via a back spinning hook kick. He collapsed to the mat and was disoriented after the stand-up.