LONDON, June 11 (Xinhua) -- American trio Emma Navarro, Amanda Anisimova and Madison Keys all advanced in the women's singles round of 16 at the Queen's Club Championships on Wednesday.

Third seed Navarro came from a set down to defeat Brazil's Beatriz Haddad Maia 1-6, 7-6(4), 6-4.

The world No. 10 struggled to find her rhythm in the opening set and faced a match point in the grueling second, but the former Wimbledon quarterfinalist gradually raised her level and sealed the win in 2 hours and 47 minutes.

Navarro will face fellow American Anisimova in the quarterfinals after the world No. 15 outplayed British wild card Sonay Kartal 6-1, 6-3.

Australian Open champion Keys overcame a shaky start to defeat Russian qualifier Anastasia Zakharova 6-3, 6-2.

Keys admitted she had trouble early on. "Once I did, I feel like I played really well," the second seed said during her on-court interview.

Meanwhile, sixth seed Karolina Muchova was knocked out of the WTA 500 event in west London by German qualifier Tatjana Maria, 6-7(3), 7-5, 6-1.

China's Olympic champion Zheng Qinwen will face American McCartney Kessler in the second round on Thursday. ■