LONDON - China's Olympic champion Zheng Qinwen reached the semifinals on grass for the first time in her career as she knocked out home sensation Emma Raducanu 6-2, 6-4 at the Queen's Club Championships on Friday.

Zheng, 22, entered the WTA 500 tournament as the top seed and received a bye in the first round.

She needed two hours and 11 minutes to beat McCartney Kessler from the United States 6-3, 4-6, 7-5 in the second round on Thursday and seemed to repeat the story on Friday as she was broken twice at the beginning of the second set.

"My first serves dropped a lot since the start of the second set and it's kind of destructive on grass court," said Zheng after the match. "My opponent was actually in a low period, but I gave her chances to come back."

"But I adjust quicker than I did in my previous match and I'm pleased that I could turn around the table in the second set," adde the world No. 5.

When Raducanu was facing breaking points in the sixth game of the first set, Zheng asked for a timeout to change for a pair of new trainers before breaking Raducanu for the first time.

"I couldn't keep going as I have slipped a few times," Zheng explained. "Since I arrived here, I was wearing the shoes from last year's Wimbledon. I know exactly when I should change shoes either on the hard court or the clay court, but I'm not sure while playing on grass. I did ask for opinion from my coach ahead of my first match. He said maybe later and I felt all right yesterday."

Zheng suffered first-round exit at the Wimbledon Championships in the past two years, but she believed she has already gained more experience from the two matches she played this year.

"I have better understanding while playing on grass and I know which shot I should use in different situations," said Zheng. "But I need to keep winning on grass and have more matches to play on the surface."

Zheng will face Amanda Anisimova on Saturday as the American defeated Emma Navarro 6-3, 6-3.

The other semifinal will be between Australian Open champion Madison Keys from the United States and German qualifier Tatjana Maria.