The third seed succumbed to an 18-21, 19-21 defeat against his seventh-seeded opponent at the Babu Banarasi Das Indoor Stadium, ending his run on day four of the Badminton World Federation World Tour Super 300 event.

Next up for Son is eighth seed Taiwanese Wang Tzu Wei, who beat Malaysia's Soo Teck Zhi 21-19, 21-12.

The other last-four encounter will see India's Sourabh Verma do battle with South Korea's Heo Kwang Hee.

Verma emerged a 21-19, 21-16 victor over Thailand's Kunlavut Vitidsarn, while Heo overcame China's Zhao Jun Peng 21-14, 19-21, 21-14.

In the women's singles, fourth seed Carolina Marín of Spain kept up her positive comeback from a serious knee injury with a 21-13, 21-16 win over Russia's Evgeniya Kosetskaya in the quarter-finals.

Standing between the reigning Olympic champion and a place in the final is South Korea's Kim Ga Eun, a 21-18, 21-14 victor at the expense of compatriot Kim Hyo Min.

Also through to the semi-finals is Thailand's Phittayaporn Chaiwan, who defeated China's Wang Zhi Yi 21-17, 21-12.

Awaiting her there is India's Rituparna Das, who defeated fellow countrywoman Shruti Mundada 24-26, 21-10, 21-19.

The semi-finals in both the men's and women's events take place tomorrow.