Men's top seed Son Wan Ho and women's favourite Sung Ji Hyun both advanced to the quarter-finals of their respective draws at the Korea Masters Championship on Thursday.
Son – who is yet to drop a game at the event – eased past fellow South Korean Kim Moon Jun 21-11-, 21-11 on the courts of the Seogwipo Olympic Stadium in Jeju.
Third seed Lee Dong Keun battled past Shih Kuei Chun of Chinese Taipei 21-17, 21-12 and sixth seed Jeon Hyeok Jin defeated Japan's Hashiru Shimono 22-20, 21-16.
In the women's draw, top seed Sung beat Lee min Ji 21-15, 21-11 and fourth seed Ayuni Mine defeated fellow Japanese Kaori Imabeppu 21-19, 21-18.
Finally, there was an upset when China's Chen Xiaoxin knocked out fifth seed Aya Ohori 21-19, 21-7.