Career
She competed at the 2010 and 2014 Asian Games. Unlike most Korean badminton players Sung has focused on singles and in December 2011 she received a career high ranking of number seven in the world in that discipline. In 2012, Sung"s performance at Super Series was progressingly better, with semi final performance in Indonesia Open, Singapore Open and Japan Open.
She was seeded 8th at the Olympics 2012.
However, her lackluster performance in the Olympics 2012 saw her failing to make past the group match, losing to Yip Pui Yin. This propelled her ranking up to world no.5, the highest of her career.
Then, she reached the finals of 2013 Denmark Super Series Premier losing to Wang Yihan in 21–16, 18–21, 20–22. In 2013 of Korea Open Grand Prix Gold, she went up against compatriot Bae Youn-joo and she was beaten in 3 sets 21–19, 15–21, 21–9.
In 2014 German Open Grand Prix Gold, She went on to the finals.
She qualified for the Dubai 2014 BWF Super Series Masters Finals and lost to Tai Tzu-ying in the final, 17-21, 12-21.
