Number one seed Lee Dong-keun is out of the BWF US Open ©Getty Images

The men’s singles semi-final line-up at the Badminton World Federation US Open in California has been confirmed – and neither of the top two seeds are involved.

South Korea’s number one seed Lee Dong-keun was beaten 21-12, 21-14 by Lin Chun-yi of Chinese Taipei at Titan Gym in Fullerton.

In an all-Indian clash, number two seed HS Prannoy was edged out 21-19, 23-21 by Sourabh Verma.

Lin Chun-yi will face Chinese Taipei’s Lin Yu-Hsien in tomorrow’s semi-final after the latter eased past Lucas Corvée of France 21-8, 21-14.

Thailand’s Tanongsak Saensomboonsuk battled back from a set down to triumph against China’s Sun Feixiang 16-21, 21-18, 21-12, setting up a duel with Verma.

In the women’s draw, top seed Michelle Li was made to work hard for her semi-final spot.

Michelle Li progressed to the last four of the women's singles at the BWF US Open ©Getty Images
Michelle Li progressed to the last four of the women's singles at the BWF US Open ©Getty Images

The Canadian edged out South Korea’s Kim Hyo-min 22-20, 21-18 and will face another South Korean, number three seed Kim Ga-eun, who beat compatriot An Se-young 21-11, 21-14.

Number six seed Ayumi Mine of Japan fought back from a set down to beat South Korea’s Sim Yu-jin 12-21, 21-18, 21-11.

She will meet Wang Zhiyi of China in the last four, the 21-14, 21-12 conqueror of Chinese Taipei’s Lin Hsiang-ti.

Meanwhile, Denmark’s world number five and HSBC Race To Guangzhou Rankings leader Viktor Axelsen could be out for more than a month with a leg injury.

Axelsen wrote on Twitter: “It’s with great sadness that I inform you I’ve been experiencing persistent pain in my leg for a few weeks now.

“After being assessed by multiple specialists, I’ve been advised not to compete in any tournaments at this moment.”