Supanida Katethong bowed out in the women's singles semi-finals of the US$1.15 million BWF China Masters 2024 in Shenzhen on Saturday.
The Thai eighth seed lost to China's Gao Fangjie 16-21, 15-21 in the World Tour Super 750 event.
Gao, winner of the Macau Open, goes on to meet Korean top seed An Se-Young, who eased past Japanese rising star Tomoka Miyazaki 21-5, 22-20.
World No.1 An is chasing her fourth title of the year. The Korean won the Malaysia Open, the French Open and the Singapore Open while finishing runner-up at the Indonesia Open and the Denmark Open.
Supanida's loss to Gao came after she had punched her ticket to the HSBC BWF World Tour Finals in Hangzhou next month, edging compatriot Pornpawee Chochuwong in a tight race.
Supanida made things easy for herself with a convincing 21-14, 21-17 win over Singapore's Yeo Jia Min in the China Masters quarter-finals on Friday.
She then awaited the outcome of the Pornpawee-Gao quarter-final. Victory for Pornpawee would have teed up a tantalising all-Thai semi-final showdown for one of the two remaining women's singles slots in Hangzhou. But that never materialised as Gao proved too strong for Pornpawee, winning 21-18, 21-14.
Earlier, mixed doubles top seeds Feng Yanzhe and Huang Dongping of China defeated Malaysian fourth seeds Cheng Tang Jie and Toh Ee Wei 21-18, 21-13 to progress to the final.
They will face Malaysians Hoo Pang Ron and Cheng Su Win, who battled past third seeds Tang Chun Man and Tse Ying Suet of Hong Kong 21-14, 17-21, 21-19.
In the men's singles semi-finals, sixth seed Jonatan Christie of Indonesia pulled off a major upset, defeating top seed Shi Yuqi of China 21-17, 21-16.
In the other semi-final, third seed Anders Antonsen of Denmark rallied to beat second-seeded compatriot Viktor Axelsen 16-21, 21-9, 22-20.