World champion Kento Momota beat Olympic champion Chen Long today ©Getty Images

Both reigning Olympic singles champions threw away leads as they exited at the semi-final stage of the Badminton World Federation Fuzhou China Open today.

China's Rio 2016 men's winner Chen Long lost on home soil to the current world champion Kento Momota of Japan in a titanic last four contest.

Momota, the world number one and top seed, recovered to beat his sixth-ranked opponent 19-21, 21-17, 21-17 at Fuzhou's Haixia Olympic Sport Center.

He will now meet Chinese Taipei's fourth seed Chou Tien-chen in the final of the World Tour Super 750 event.

The Taiwanese player ended home interest by knocking out China's second seed and World Championship runner-up Shi Yuqi, 21-11, 21-10.

China's Chen Yufei ended the run of Carolina Marin ©Getty Images
China's Chen Yufei ended the run of Carolina Marin ©Getty Images

In the women's draw, Olympic champion Carolina Marin suffered the same fate as Chen.

The Spanish fifth seed, also the reigning world champion, went in front but was beaten by China's home fourth seed Chen Yufei.

The host nation player advanced 11-21, 21-15, 21-13.

Japan's 2017 world champion Nozomi Okuhara also made final, with the seventh seed beating eighth-seeded Chinese He Bingjiao 21-13, 21-13.

The finals will be played tomorrow when the doubles events will also conclude.