Nozomi Okuhara beat Ratchanok Intanon to claim the women's singles title while Son Wan-ho overcame Kenta Nishimoto to clinch the men's title.
Kidambi Srikanth, who had reached number one in world badminton rankings, has taken a dip since his loss in 2018 Commonwealth Games final.
Kento Momota lost 21-18, 16-21, 19-21 to Son Wan-Ho in an exhausting 89 minutes -- the longest match of the tournament so far.
Kidambi Srikanth lost to Kenta Nishimoto while Sameer Verma lost out to Lee Cheuk Yiu in the quarter-finals of Hong Kong Open.
PV Sindhu was sent packing by South Korean Sung Ji Hyun.
Saina Nehwal fell in a first round as she lost to Akane Yamaguchi of Japan in three games.
PV Sindhu beat Nitchaon Jindapol of Thailand in the first round.
PV Sindhu lost to eighth seed He Bingjiao, while Kidambi Srikanth lost to Chou Tien Chen in China Open quarterfinals.
Lee Chong Wei made his first public appearance since his shock nose cancer diagnosis was announced in September.
PV Sindhu will next face world no. 7 He Bingjiao of China while Kidambi Srikanth will lock horns with Taipei's Chou Tien Chen in the quarter-finals on Friday.
Kidambi Srikanth brushed aside France's Lucas Corvee in 35 minutes. He will now face Indonesia's Tommy Sugiarto in the next round.
PV Sindhu beat Evgeniya Kosetskaya 21-13, 21-19 to march into China Open second round.
Both Saina Nehwal and Kidambi Srikanth were knocked out after losing their respective quarter-finals match in the French Open 2018.
French Open 2018: Kidambi Srikanth lost to top seeded Kento Momota in men's singles quarters.
PV Sindhu beat Japan's Sayaka Sato in 46 minutes to enter the women's singles quarterfinals of the French Open 2018.
Saina Nehwal has now defeated Japan's Nozomi Okuhara two times in two weeks.
Saina Nehwal will meet Nozomi Okuhara in round two of the French Open 2018.