Despite playing far from her best tennis, China's world No 7 Zheng Qinwen battled past rising Russian star Mirra Andreeva on Friday to reach the semifinals of the China Open for the first time, keeping alive her hopes of a major tournament win on home soil.

Zheng, the overwhelming crowd favorite at the Beijing tournament, stepped up a gear after losing the first set and kept her title ambition on track, as she overcame the 17-year-old 5-7, 6-0, 6-4, to reach the last four of a tournament in the elite WTA1000 class for the first time.

The next opponent for the reigning Olympic singles champion and 5th seed will be US Open semifinalist Karolina Muchova of the Czech Republic. Their match-up on Saturday will be a replay of the Palermo Open final in July, won by Zheng.

Muchova reached the last four with a surprise three-set win over Belarusian top seed Aryna Sabalenka.

Despite her bitter rival Sabalenka now being out of contention, Zheng said she is prepared for a tough encounter against Muchova.

"She's such a smart player that I found quite hard to compete against in our previous match," said Zheng after her win over Andreeva, which took more than two and a half hours in front of a packed house on Beijing's Diamond Court.

"To be honest, I am kind of surprised that she beat Sabalenka today, which suggests she is in really good form. I will do my best for sure facing her again.

"I started a little bit slow today, not quite familiar with my opponent's style of play, so I had a lot of unforced errors in the first set. Yet gradually I got used to how she played and figured out how to counter her game," Zheng said of her comeback against Andreeva, a semifinalist at this year's French Open.

Zheng, 21, has become the first Chinese semifinalist in Beijing since Wang Qiang in 2018.