Dhaka, June 14 -- China's Olympic champion Zheng Qinwen fought hard to reach the quarter-finals of the women's singles at the Queen's Club Championships on Thursday.

The 22-year-old Zheng, ranked world No. 5, needed two hours and 11 minutes to overcome McCartney Kessler of the United States 6-3, 4-6, 7-5 in the second round.

Zheng entered the WTA 500 tournament as the top seed and received a bye in the first round. She said she didn't expect her first match on grass this season to be easy - and she was indeed tested Thursday evening.

Zheng admitted she lost focus briefly after taking the opening set and struggled to adjust in time.World No. 42 Kessler broke in the 10th game of the second set to even the match and then broke first in the ...