Wang Yihan of China hits a return during the women's singles quarter-final match of the Yonex-Sunrise India Open 2014 against Saina Nehwal of India in New Delhi, India, April 4, 2014. Wang Yihan won 2-0 and entered the semi-final. (Xinhua/Partha Sarkar)

Lee Chong Wei of Malaysia hits a return during the men's singles quarter-final match of the Yonex-Sunrise India Open 2014 against Kashyap Parupalli of India in New Delhi, India, April 4, 2014. Lee Chong Wei won 2-0 and entered the semi-final. (Xinhua/Partha Sarkar)

Wang Yihan of China hits a return during the women's singles quarter-final match of the Yonex-Sunrise India Open 2014 against Saina Nehwal of India in New Delhi, India, April 4, 2014. Wang Yihan won 2-0 and entered the semi-final. (Xinhua/Partha Sarkar)

Saina Nehwal of India hits a return during the women's singles quarter-final match of the Yonex-Sunrise India Open 2014 against Wang Yihan of China in New Delhi, India, April 4, 2014. Saina Nehwal lost 0-2. (Xinhua/Partha Sarkar)

Wang Yihan of China reacts after the women's singles quarter-final match of the Yonex-Sunrise India Open 2014 against Saina Nehwal of India in New Delhi, India, April 4, 2014. Wang Yihan won 2-0 and entered the semi-final. (Xinhua/Partha Sarkar)

Saina Nehwal of India hits a return during the women's singles quarter-final match of the Yonex-Sunrise India Open 2014 against Wang Yihan of China in New Delhi, India, April 4, 2014. Saina Nehwal lost 0-2. (Xinhua/Partha Sarkar)

Lee Chong Wei of Malaysia hits a return during the men's singles quarter-final match of the Yonex-Sunrise India Open 2014 against Kashyap Parupalli of India in New Delhi, India, April 4, 2014. Lee Chong Wei won 2-0 and entered the semi-final. (Xinhua/Partha Sarkar)