Japan's Aya Ohori is the only unseeded player to reach the women's singles semi-finals at the BWF Thailand Masters ©Getty Images

Japan's Aya Ohori upset the odds to beat second-seeded home player Ratchanok Intanon and reach the women's singles semi-finals, at the Badminton World Federation (BWF) Thailand Masters in Bangkok.

Ohori, the world number 20, came storming back from a game down to claim a 16-21, 21-17, 21-11 win over the 2016 champion on day four of the World Tour Super 300 event at Indoor Stadium Huamark.

Her reward is a last-four encounter with third-seeded South Korean An Se-young, who defeated France's Qi Xuefei 21-11, 21-12.

The other semi-final pits top seed Akane Yamaguchi of Japan against fourth seed Carolina Marín of Spain, after both recorded straight-game victories today.

Yamaguchi overcame Indonesia's Gregoria Mariska Tunjung 25-23, 21-14, while Marín beat Japan's Sayaka Takahashi 21-9, 21-16.

Second seed Shi Yuqi of China remains on course to win the men's singles title ©Getty Images
Second seed Shi Yuqi of China remains on course to win the men's singles title ©Getty Images

In the men's singles event, second-seeded Chinese Shi Yuqi booked his place in the penultimate round by beating Indonesia's Shesar Hiren Rhustavito 21-19, 21-15.

Next up for him is third seed Ng Ka Long Angus of Hong Kong, who defeated South Korea's Heo Kwang-hee 21-16, 13-21, 21-11.

Also through to the semi-finals is 18-year-old home player Kunlavut Vitidsarn, who overcame fellow Thai Suppanyu Avihingsanon 21-10, 21-17.

Standing between him and a place in the final is Japan's Kenta Nishimoto, a 21-11, 22-20 winner over China's Zhao Junpeng.

Action in Bangkok continues tomorrow, with the finals scheduled for Sunday (January 26).