The 25-year-old Japanese player is chasing a 10th title of 2019. (Photo: AFP)

Defending champion and world number one Kento Momota battled past former number one Viktor Axelsen to reach the Fuzhou China Open semi-finals on Friday.

The 25-year-old Japanese, who is chasing a 10th title of 2019, suffered a second-game wobble before winning 21-18, 12-21, 21-16 in their quarter-final.

Momota will play Axelsen's fellow Dane Rasmus Gemke, who is unseeded, in the last four on Saturday.

Victory for the all-action Momota, the reigning two-time world champion, was his 13th in 15 matches against Axelsen, now ranked sixth in the world.

"I'm getting closer and closer," the 25-year-old Axelsen, whose career has recently been disrupted by injury, said after forcing Momota to three games.

The other semi-final is between the second seed Chou Tien-chen of Taiwan and another Dane, Anders Antonsen.

In the women's draw, world number one Tai Tzu-ying of Taiwan faces Japan's world number two Nozomi Okuhara in the semi-finals.

Tai was forced to fight for her spot in the last four, defeating unseeded Kim Ga-Eun of South Korea 21-15, 11-21, 21-13.

The second semi-final is between reigning Fuzhou champion Chen Yufei, the home hope, and unseeded Michelle Li of Canada.