Chen had minimal difficulty seeing off Soniia Cheah Su Ya of Malaysia, overcoming the unseeded player 21-15, 21-8 at Huamark Indoor Stadium in Bangkok.

She is set to face another unseeded player, Sayaka Takahashi of Japan, in the semi-finals after she defeated Fitriani of Indonesia following a to-and-fro encounter, winning 22-20, 15-21, 21-14.

Thailand are guaranteed a player in the women's final, with Ratchanok Intanon and Pornpawee Chochuwong due to meet in tomorrow's semi-final.

Sixth seed Intanon earned a straight set win over Chen Xiaoxin of China, 21-17, 21-15, while the unseeded Chochuwong had to work harder to earn a final four place in her home tournament.

Chochuwong eventually won in three sets against Cheung Ngan Yi of Hong Kong, 21-15, 15-21, 21-12.

In the men's draw, the two highest ranked players left in the quarter-finals met as third seed Chou Tien-chen of Taiwan faced Japanese sixth seed Kenta Nishimoto.

Chou continued his impressive form in Thailand, winning 21-12, 21-16 to ensure he is yet to drop a set in this competition.

Japan do still have a male singles representative, however, with seventh seed Kanta Tsuneyama proving too strong for India's unseeded Sai Praneeth Bhamidipati, winning 21-18, 21-12.

Chou is scheduled to face Malaysia's unseeded Lee Zii Jia in the last four, after he ended the run of Indonesian qualifier Shesar Hiren Rhustavito, 11-21, 21-14, 21-13.

Tsuneyama, meanwhile, will play Angus Ng Ka Long of Hong Kong tomorrow, after he beat the final Thai representative in the men's singles, Khosit Phetpradab, 22-20, 17-21, 21-17 after a gruelling 69-minute encounter.