In Sydney Yun placed 4th in the individual ranking round with a score of 661. In the first elimination round she beat Erika Reyes of Mexico 168-157. In the round of 32, she defeated Anna Karaseva of Belarus 162-152. In round 16, she broke the Olympic record in women's 18-arrow match in defeat of Alison Williamson of Great Britain 173 to 164.
In the quarterfinals, Yun defeated Natalia Bolotova of Russia 110-105 in a 12-arrow match, and in the semi-finals the eventual bronze-medalist and compatriot Kim Soo-nyung 107-105. In the final, she captured the gold by a mere point, when Yun defeated Kim Nam-soon 107-106.
In Athens, Yun placed 3rd in the women's individual ranking round with a 72-arrow score of 673. In the first round of elimination, she faced 62nd-ranked Hanna Karasiova of Belarus. Yun defeated Karasiova 162-155 in the 18-arrow match to advance to the round of 32. In that round, she faced 35th-ranked Japanese archer Sayami Matsushita, defeating 173-149 and tying her own Olympic record for score in an 18-arrow match. Yun then defeated 19th-ranked Jennifer Nichols of the United States 168-162, advancing to the quarterfinals.
In the quarterfinals, Yun faced Yuan Shu-chi of Chinese Taipei, losing to the 6th-ranked archer to end the Korean team's hopes of sweeping the medals. The final score of 107-105 in the 12-arrow match placed Yun 5th overall in women's individual archery.
She competed in the 2002 Asian Games, where she won a gold medal in the team event and a bronze medal in the individual event, and at the 2006 Asian Games where she won a gold medal in the team event.[2]
