Ratchanok Intanon and Pornpawee Chochuwong advanced to the quarter-finals of the US$1 million (32.5 million baht) BWF Singapore Open on Thursday, but defending champion Kunlavut Vitidsarn retired with an injury.
Sixth seed Ratchanok, winner of the Malaysia Masters on Sunday, moved past Japan's Natsuki Nidaira 21-10, 21-16 while Pornpawee ousted Taiwan's Lin Hsiang-ti 21-15, 21-16.
Next up for Ratchanok is a match against old rival Akane Yamaguchi of Japan. The third seed downed Michelle Li of Canada 21-14, 21-6 on Thursday.
Pornpawee will have an equally tough assignment against second seed and world No.2 Wang Zhiyi of China in the last eight of the Super 750 tournament.
Mixed doubles defending champions Dechapol Puavaranukroh and Supissara Paewsampran also came through their last-16 clash in two games. The Thai second seeds cruised past Chen Zhi Yi and Francesca Corbett of the United States 21-6, 21-11.
Kunlavut's campaign ended in the last 16 yesterday after the world No.2 retired early in the first game with a back injury during his match against Lakshya Sen of India.
Mixed doubles pair Pakkapon Teeraratsakul and Sapsiree Taerattanachai, finalists in Kuala Lumpur on Sunday, also exited the tournament after losing to seventh seeds Tang Chun Man and Tse Ying Suet of Hong Kong 19-21, 13-21.
Women's doubles players Phattharin Aiamvareesrisakul and Sarisa Janpeng were sent packing by eighth seeds Gabriela Stoeva and Stefani Stoeva of Bulgaria 8-21, 13-21 in just 28 minutes.
Aimsaard sisters -- Benyapa and Nuntakarn -- continued to fly the flag for Thailand in the women's doubles event, advancing to the quarter-finals with a 21-16, 21-19 win over second seeds Tan Pearly and Thinaah Muralitharan of Malaysia.
They will play Arisa Igarashi and Chiharu Shida of Japan in the last eight.
Former champion An Se-Young of South Korea stormed into the last eight with a 21-8, 21-6 win over Sung Shuo-yun of Taiwan. The world No.1 will play Pusarla V Sindhu of India.
