COPENHAGEN, Aug. 29 (Xinhua) -- Badminton top players Lee Chong Wei and Li Xuerui entered the singles semifinals by winning in straight sets at 2014 world championships held at Ballerup Super Arena, Copenhagen, on Friday.

Men's top seed Lee Chong Wei of Malaysia beat sixth seed Wang Zhengming of China 21-8, 21-11 to book a berth in the top four.

As China's men's single top gun, second-seeded Chen Long defeated No. 7 seed Wan Ho Son of South Korea 21-14, 12-21, 21-17 to reach the semifinals, in a marathon match lasting 86 minutes. He will face the challenge from fifth-seeded Tommy Sugiarto of Indonesia.

In women's singles, London Olympics champion and top seed Li Xuerui of China carved out a 21-15, 21-15 victory over Olympic bronze medallist Saina Nehwal of India in 45 minutes. She will meet Japan's Minatsu Mitani, who beat the fifth-seeded Ji Hyun Sung of South Korea 9-21, 21-18, 22-20.

Meanwhile, eleventh seed Sindhu P. V. of India caused a huge upset with her aggressive style, beating second seed Wang Shixian of China in three sets 19-21, 21-19, 21-15.

In men's doubles, South Korea has secured three berths in semifinals after second seeds Yong Dae Lee/Yeon Seong Yoo beat Sheng Mu Lee/Chia Hsin Tsai of Chinese Taipei 21-16, 21-13. They will meet Denmark's top duo Mathias Boe/Carsten Mogensen, also last year's silver medalists, in Saturday's semifinals.

Olympics champions Wang Xiaoli/Yu Yang overcame their twin compatriots Luo Ying/Luo Yu 21-11, 21-11 in women's doubles while Tian Qing/Zhao Yunlei beat Indonesian pair Anggia Shitta Awanda/ Della Destiara Haris in two sets.

Mixed doubles top seeds Zhang Nan/Zhao Yunlei of China took just 32 minutes to beat Thailand's Sudket Prapakamol/Saralee Thoungthongkam 21-13, 21-9. They will meet another Chinese duo of Liu Cheng/Bao Yixin in the semifinals, while second seeds Xu Chen/ Ma Jin also secured a quick win over their Hong Kong opponents.