Ratchanok Intanon suffered a shock defeat in the opening round of the US$1 million China Open in Changzhou yesterday.
The Thai fourth seed bowed out to Zhang Beiwen of the US 21-9, 16-21, 16-21 in their first round encounter at the Olympic Sports Center Xincheng Gymnasium.
World No.4 Ratchanok easily took the first game and looked set to coast to a routine win against the 12th-ranked Zhang. However the Thai took her foot off the gas pedal in the second, allowing Zhang to pull level before an error-filled third game wrecked her confidence.
Zhang goes on to play Gregoria Mariska Tunjung of Indonesia today.
Thai hopes in the women's singles event will now rest on Nitchaon Jindapol and Pornpawee Chochuwong after both advanced to the second round.
Nitchaon beat Cai Yanyan of China 21-14, 21-18 to set up a meeting with Gao Fengjie, who stunned top seed and world No.1 Tai Tzu-ying in the opener yesterday.
Pornpawee went through following a 21-15, 21-12 victory over Soniia Cheah of Malaysia. She next faces eighth seed Nozomi Okuhara of Japan.
Suppanyu Avihingsanon advanced to the men's singles second round after beating Mark Caljouw of the Netherlands 22-20, 21-17. He faces seventh seed Srikanth Kedambi of India for the a place in the quarter-finals.
Compatriot Kantaphon Wancharoen will meet fifth seed and Asian Games silver medallist Chou Tien-chen of Taiwan in the other second round match today.
In the men's doubles, Tinn Isriyanet and Kittisak Namdash beat Jason Anthony Ho-Shue and Nyl Yakura of Canada 21-14, 21-9. Next up for the Thai pair is a tough assignment against top seeds Marcus Fernaldi Gideon and Kevin Sanjaya Sukamuljo of Indonesia.
In the mixed doubles, world No.11 pair Dechapol Puavaranukroh and Sapsiree Taerattanachai cruised past Praveen Jordan and Melati Daeva Oktavianti of Indonesia 21-11, 21-13. They play eighth seeds Chris Adcock and Gabrielle Adcock of England in the next round.
No Thais were left in the women's doubles event after Thanapim Kaweenuntavong and Peeraya Khantaruangsakul lost to Gabriela Stoeva and Stefani Stoeva of Bulgaria 15-21, 7-21.