08/02/2012 09:19 EDT | Updated 10/02/2012 05:12 EDT

Top 3 Chinese women into Olympic badminton semifinals at Wembley Arena plus India's Nehwal

LONDON - World champion Wang Yihan led compatriots Wang Xin and Li Xuerui into the Olympic badminton semifinals on Thursday, with only India's Saina Nehwal standing in the way of a Chinese sweep of women's singles.

China was already ensured of at least one gold medal when both of its top-seeded pairs reached the mixed doubles final. Top-ranked Zhang Nan and Zhao Yunlei will face second-ranked Xu Chen and Ma Jin after both teams came back from losing the first game of their semifinals to make Friday's final.

The competition continued without the controversy that marred the event the past two days. On Tuesday, four women's doubles teams lost their matches on purpose to ensure a more favourable draw in the next round, and were booed off the court.

On Wednesday, badminton's ruling body kicked the eight players involved out of the games, and the IOC said Thursday it would urge the Chinese, South Korean and Indonesian national Olympic committees to investigate the coaches of the players.

Wang Yihan faced a rematch of last year's worlds final with Cheng Shao-chieh of Taiwan, and Wang conceded the same number of points in the same amount of time as she won 21-14, 21-11.

Wang Xin, who held the No. 1 ranking before Wang Yihan to January last year, was given a fright by Thai 17-year-old Ratchanok Intanon before prevailing 17-21, 21-18, 21-14. Ratchanok was three points from victory but couldn't close the deal, then was hampered by a right foot injury halfway through the third game.

Then Li Xuerui, who came out of nowhere this year to earn a last-minute Olympic berth, beat Yip Pui Yin of Hong Kong 21-12, 22-20, winning the last game from 20-16 down.

Wang Xin has won all five previous matches against Li Xuerui, but their semifinal will be their first match of the year, and Li has won 34 of her last 35 matches.

Nehwal beat Danish veteran Tine Baun 21-15, 22-20, and despite never having beaten Wang Yihan, she will carry a 14-match winning streak into their semifinal.

In mixed doubles, Zhang and Zhao, the world champions, won a close game from Joachim Fischer and Christinna Pedersen of Denmark 17-21, 21-17, 21-19 in 82 minutes.

Xu and Ma beat Tontowi Ahmad and Liliyana Natsir of Indonesia 21-23, 21-18, 21-13 in 75 minutes. Natsir won the mixed doubles silver medal in Beijing, and will play for bronze against the Danes.

The defeat of Ahmad and Natsir meant Indonesia will not win badminton gold at an Olympics for the first time.