QINGDAO, China - The world No 1 shuttler Wang Yihan of China was stunned by her teammate Li Xuerui 2-1 at the finals of the Asian badminton championships on Sunday.

After losing the first set 21-16, the 24-year-old Wang fought back to clinch a 21-16 second set win against the fourth-ranked Li.

The deciding set was one-sided as Wang was beaten 21-9.

World No 1 Wang Yihan of China returns a shuttlecock to Li Xuerui during their women's singles finals at the 2012 Asian badminton championships in Qingdao, April 22, 2012. [Photo/Xinhua]

"I had too many faults in the game, especially in the third set," Wang said. "I will try to overcome my weaknesses in future training."

"I'm familiar with Wang's style," said the in-form Li, who grabbed her third title after the German Open and All-England Open titles recently. "I did well today and I will try my best to get a ticket to the London Olympics."

The 21-year-old Li is on the verge of clinching an Olympic ticket as she is ranked fourth in the Olympic ranking ahead of India's Saina Nehwal, but the 21-year-old still needs sound performance in next India competition India Superseries - the final Olympic qualification - to ensure her ticket.

Chen Jin also registered his third consecutive title in recent three tournaments as he triumphed after beating teammate Du Pengyu 21-12, 21-18 in the finals on Sunday.

The world No 5 Chen is only one step away from qualifying for the London after he advanced to No 4 based on points collected during the Olympic period after the victory in Qingdao.

Chen needs to secure the fourth place until the end of April to ensure his Olympic ticket.

Zhao Yunlei was in contention for two titles after entering the women's doubles and mixed doubles finals.

In the women's doubles, she and Tian Qing cruised past youngsters Bao Yixin/Zhong Qianxin 21-14, 21-15, while in the mixed doubles, she and Zhang Nan defeated Xu Chen/Ma Jin 21-13, 21-12.

In the men'doubles final, South Korea's Kim Ki Jun/Kim Sa Rang beat Hiroyuki Endo/Kenichi Hayakawa of Japan 21-12, 21-16.

Victories in Switzerland, Australia and the Asia championships boosted Chen's hopes for an Olympic ticket as his close rival, Denmark's Peter Gade, suffered a surprise quarterfinal defeat at the European championships.

"I don't have time to relax. I was playing all the time in the last two months and feel tired both physically and mentally, but in order to gain more Olympic points, I have to adjust to it," said Chen, who enjoyed a walkover after his semifinal opponent Lin Dan pulled out due to waist injury on Saturday.

Li Xuerui of China returns a shuttlecock to Wang Yihan during their women's singles finals at the 2012 Asian badminton championships in Qingdao, April 22, 2012. [Photo/Xinhua]