Ratchanok Intanon and Pornpawee Chochuwong will square off in the women's singles quarter-finals of the US$210,000 BWF Madrid Spain Masters on Friday.
The Thai stars came through their last-16 clashes on Thursday with two-game victories to set up an all-Thai clash at the BWF World Tour Super 300 event in the Spanish capital.
Fourth seed Ratchanok needed just 37 minutes to defeat her Scottish opponent Kirsty Gilmour 21-14, 21-17 in the last 16 on Thursday.
Fifth seed Pornpawee, the 2020 champion, defeated Putri Kusuma Wardani of Indonesia 21-14, 22-20.
Ratchanok, 29, was knocked out in the first round in her last three tournaments -- the French Open, the All England Open and the Swiss Open -- and has yet to get past the quarter-final stage in eight events since the start of the season in January.
Pornpawee defeated Spain's Carolina Marin to win the 2020 tournament for one of her two career World Tour titles. The 26-year-old's other World Tour victory was in the 2023 Swiss Open.
Supanida Katethong and Pornpicha Choeikeewong are the other two Thai players in the women's singles event.
Sixth seed Supanida was due to play Natsuki Nidaira of Japan while Pornpicha was to face Michelle Li of Canada later last night.
Men's singles player Kantaphon Wangcharoen also advanced to the last eight on Thursday.
The 25-year-old star defeated Jeon Hyeok-Jin of South Korea 21-18, 21-17 and will next play eighth seed Toma Junior Popov after the French eighth seed eliminated Su Li-yang of Taiwan 21-16, 21-15 to advance.
Kantaphon is the only Thai in the men's singles draw.
Last year's runner-up Pusarla V Sindhu of India secured her quarter-final berth with a 21-14, 21-12 victory over Huang Yu-hsun of Taiwan.
Ester Nurumi Tri Wardoyo of Indonesia also progressed after beating Nguyen Thuy Linh of Vietnam 21-12, 21-15.
Second seed Sindhu will play the winner of the Supanida v Nidaira match in the last eight while Wardoyo will next face either third seed Kim Ga-Eun of South Korea or Liang Ting-yu of Taiwan.
In the women's doubles last 16, Chang Ching-hui and Yang Ching-tun of Taiwan overcame Annie Xu and Kerry Xu of the US 21-12, 17-21, 21-19 while Keng Shuliang and Zhang Chi of China defeated Maiko Kawazoe and Haruna Konishi of Japan 21-10, 21-18.
Also, mixed doubles duo Chen Cheng-kuan and Hsu Yin-hui of Taiwan came from behind to defeat home players Ruben Garcia and Lucia Rodriguez 15-21, 21-17, 21-14 to progress.