Hong Kong's Zhou Mi and Wang Chen reached the women's singles semi-finals at the Korea Super Series event in Seoul, but it was mixed doubles pair Yohan Wiratama and Chau Hoi-wah who stole the limelight yesterday. The pair defeated Britain's Robert Blair and Imogen Bankier 2-0 to reach the last four in a Super Series tournament for the first time. Top seed and defending champion Zhou breezed past Petya Nedelcheva of Bulgaria 21-16, 21-17 and now meets France's Pi Hongyan. Wang, who beat Korean Hwang Hye-youn 18-21, 21-19, 21-14, will take on second seed Tine Rasmussen of Denmark. Chan Yan-kit lost to Przemyslaw Wacha of Poland in his last-eight clash.