Birmingham: Five times champion Lin Dan of China fought off a tenacious challenge from compatriot Tian Houwei to reach the men's singles last eight at the All England Open Badminton Championships here.
The two-time Olympic champion and five times World Champion beat the 23-year-old Tian 21-15, 21-19 at the Barclaycard Arena on Thursday, reports Xinhua.
"Nobody wants to meet teammates at such an early stage. Houwei played smartly but may be he has put himself under too much pressure," the 31-year-old Lin said.
Trailing 3-6 in the second game, Tian scored six points in a row for a 9-6 lead with powerful smashes. The scoreline was levelled several times until Tian made it 18-18. But Lin, nicknamed Super Dan, gave no chance to his compatriot, winning 21-19 and reaching the quarter-finals.
Top seed Chen Long, last year's beaten finalist, crushed Hsu Jen Hao of Chinese Taipei 21-7, 21-9.
Fifth-seeded Lin will next take on Japan's Kento Momota while Chen faces Chou Tien Chen of Chinese Taipei.
In women's singles, China's top seed Li Xuerui suffered a surprise defeat to less known compatriot Sun Yun. The 2012 winner was beaten 13-21, 13-21 by the 21-year-old Sun.
"I have tried my best but I have not entirely recovered from my foot injury yet. I only started training again about two weeks ago," Li said.
Second seed Wang Shixian of China beat Bae Yeon Ju of South Korea 21-12, 13-21, 21-9 while compatriot Wang Yihan saw off Japan's Minatsu Mitani 21-23, 21-6, 21-16.
Sixth seed and reigning World Champion Carolina Marin of Spain also advanced to the last eight with a win over Porntip Buranaprasertuk of Thailand 21-10, 21-16.