NANJING, China (AP) -- Five-time champion Lin Dan fell to Chinese compatriot Shi Yuqi again while No. 1s Viktor Axelsen and Tai Tzu Ying moved into the quarterfinals at the world badminton championships on Thursday.
Lin lost to Shi, 12 years his junior, 21-15, 21-9. Shi pulled away early in the first game. In the second, a six-point string to 13-6 put Shi in control.
Lin hasn't won the championships in five years but he was runner-up last year at 33, and can't be underestimated.
Shi beat him for the third time this year, including in a thrilling All England final, and for the fifth time in six career meetings.
Axelsen defeated Angus Ng Ka Long of Hong Kong 21-19, 21-18, overcoming early leads by Ng in both testing games.
"I didn't feel that good on court, to be honest," Axelsen said. "My opponent definitely made it tough for me."
The top-seeded Dane will next face Olympic champion Chen Long, whom he beat in the semifinals of last year's worlds en route to the title.
Chen beat No. 14-seeded Kenta Nishimoto 21-18, 21-19.
Unseeded Darren Liew of Malaysia upset fifth-seeded Kidambi Srikanth of India 21-18, 21-8, and joined Asian champion Kenta Momota and Chou Tien Chen in the quarterfinals.
Tai beat Zhang Beiwen of the United states 21-19, 21-14 in what seems to be an inexorable march to her first world title.
Tai has looked unstoppable in 2018, with only one loss in 36 matches. Her lone defeat came against Ratchanok Intanon in January in the Malaysia Masters final.
Ratchanok, the 2013 world champion, was defeated by Saina Nehwal of India 21-16, 21-19. The result was an upset on seedings but not on history. Nehwal has won 10 of their 15 matchups, including the last four.
Second-seeded Akane Yamaguchi of Japan eased past Nitchaon Jindapol of Thailand in straight games to advance, along with No. 5 Chen Yufei and No. 6 He Bingjiao of China.
Also through were two-time world champion Carolina Marin, and defending champion Nozomi Okuhara.
Marin meets Nehwal, and Okuhara will play third-seeded Pusarla Sindhu of India in a repeat of last year's final.