Kunlavut Vitidsarn and Sitthikom Thammasin bowed out in the men's singles first round of the BWF World Championships 2021 in Huelva, Spain, on Sunday.
Kunlavut, who was runner-up to Olympic champion Viktor Axelsen of Denmark in the World Tour Finals in Indonesia early this month, lost to China's Lu Guangzu 16-21, 12-21.
Another Thai hope Sitthikom was beaten by fourth seed Chou Tien-chen of Taiwan 12-21, 10-21.
Lu and Chou will face off in the second round.
Women's singles hope Phittayaporn Chaiwan was due to face Aliye Demirbag of Turkey in Sunday's late match.
The losses of Kunlavut and Sitthikom mean Kantaphon Wangcharoen, the 16th seed, is the only Thai player left in the men's singles competition. He faces Felix Burestedt of Sweden in his opener on Monday.
Also on Monday, mixed doubles pair Supak Jomkoh and Supissara Paewsampran play Fabricio Farias and Jaqueline Lima of Brazil while Benyapa Aimsaard and Nuntakarn Aimsaard take on Serena Au Yeong and Katharina Hochmeir of Austria in the women's doubles event.
In the women's singles event, second seed Ratchanok Intanon, ninth seed Pornpawee Chochuwong and 11th seed Busanan Ongbamrungphan have all received a first-round byes and will begin their campaign in the round of 32.
Mixed doubles stars Dechapol Puavaranukroh and Sapsiree Taerattanachai, the second-seeded pair, also have a first-round bye.
The duo replaced China's Zheng Siwei and Huang Yaqiong as world No.1 after retaining their World Tour Finals crown in Bali.
The Chinese pair are also competing in Huelva this week and the top seeds will start in the round of 32.
Men's singles defending champion Kento Momota has withdrawn from the tournament with a back injury while most Indonesian players have pulled out due to coronavirus concerns.
The Japanese world No.2's back problem had already forced him to withdraw from the World Tour Finals.
All Indonesian players who are members of the country's national body have withdrawn from the championships over virus worries, the Badminton World Federation (BWF) said.
Spain, where the event is taking place from Dec 12 to 19, is facing a surge in Covid-19 cases. bangkok post/afp
