Kunlavut Vitidsarn will battle Jonatan Christie in the final Group B match on Friday with a place in the men's singles semi-finals of the season-ending BWF World Tour Finals in Hangzhou, China, at stake.
Kunlavut lost to Shi Yuqi 21-14, 19-21, 23-25 in the second group match on Thursday as the Chinese star became the first player to qualify for the last four of the men's singles event at the Hangzhou Olympic Sports Center Gymnasium.
World champion and Olympic silver medallist Kunlavut, who now has one win and one loss in Group B, will need to beat Christie of Indonesia in a winner-takes-all clash today to join Shi in the semi-finals of the US$2.5 million tournament.
Christie rebounded from his opening loss to Shi on Wednesday as he beat Kodai Naraoka of Japan 21-12, 21-11, sending the Japanese star tumbling out after two successive losses.
Shi will play Naraoka on Friday.
Women's singles hopes Supanida Katethong and Busanan Ongbamrungphan suffered their second defeats on Thursday.
Finals debutant Supanida was beaten by China's Han Yue 16-21, 18-21 in a Group B clash.
The left-hander also lost to South Korea's An Se-Young in her opening match on Wednesday.
In Group A, Busanan put up a brave fight against Gregoria Mariska Tunjung before falling to the Indonesian star in three games, 21-10, 10-21, 11-21.
Busanan lost her opening match to China's Wang Zhiyi 19-21, 14-21 on Wednesday.
Japan's Aya Ohori beat China's Wang Zhiyi 21-17, 13-21, 21-19 in the other Group A match on Thursday.
Supanida will play Japan's Akane Yamaguchi while Busanan will meet Ohori in their final group matches on Friday.
Tunjung will face Wang in the final group match, with the winner joining Ohori in the semi-finals.