Zheng Qinwen, the brightest of China’s growing cohort of bright tennis lights, was 7 years old when she first picked up a racket.

Almost instantly, she was among the best children her age in her hometown, Shiyan, by Chinese standards a smaller city with 1.1 million people. She loved the sport, and after two months she and her father traveled to Wuhan, a few hours’ drive away and with a population of more than 11 million people, to show off her game to a more advanced coach. The opportunity thrilled her, and she soaked up compliments.

Her father, however, left out one detail, which she only learned after the hitting session. Since she had done well, she would not be coming home with him and instead would stay in Wuhan to train.

“I cried a lot,” Zheng, 20, said during a recent interview.

The situation got a little better when her family rented an apartment in Wuhan and her grandparents took turns taking care of her. But every two weeks when her parents would come to visit, she would beg them not to go.

The memories of those days remain painful. Being a sports prodigy in China, where it has not been uncommon for young children to grow up in sports academies and spend long periods away from their families from a young age, is not for the faint of heart. In Zheng’s case though, at least the hardship is paying off on the court.

Zheng, who is ranked 23rd in women’s singles, has battled through four matches at the U.S. Open and is getting better with each one. On Monday night she beat Ons Jabeur, a three-time Grand Slam tournament finalist, for one of the best wins of her career. On Wednesday, she will face Aryna Sabalenka, who will become the world No. 1 when the new rankings come out on Monday, in her first career major quarterfinal.

Zheng and every young Chinese player carries a unique burden onto the tennis court, especially now. Their generation came of age as part of the tennis boom that Li Na and, to a lesser extent, Peng Shuai, wrought to the country. Both, especially Li, who became the first person from China to win a Grand Slam singles title, were groundbreaking figures, inspiring countless children in China and in the Chinese diaspora to pick up tennis rackets. With more than one billion people, China figured to be in prime position to become the next great tennis power.

While that has not happened yet — though earlier this year Wu Yibing became the first Chinese player to win an ATP title — Zheng has been a prospect to watch for several years now. After roughly three years in Wuhan, she moved to Beijing, to train at an academy overseen by Carlos Rodriguez, who coached Li, her tennis idol. She also caught the attention of the same agency that had represented Li and earned an opportunity to move to Barcelona to train among the sport’s top rising stars and be closer to the world’s most competitive junior tournaments.

This time, her parents thought that was too far for their daughter to travel on her own. Her mother decided to move with her while her father remained in China, and her mother has mostly been with her ever since. She turned professional at 15, and began a mostly steady climb up the rankings.

At the French Open last year, she appeared on the verge of a breakthrough, winning the opening set of her match against top-ranked Iga Swiatek before succumbing to menstrual cramps. But then her progress seemed to stall.

This spring, her management team reached out to Wim Fissette, a Belgian known as one of the top coaches in the game. Fissette has previously worked with a slew of Grand Slam singles champions, including Kim Clijsters, Simona Halep, Angelique Kerber and Naomi Osaka.

In Zheng he saw an explosive, athletic player, but a young woman who still seemed fairly raw. He did some due diligence and learned she had a reputation as a hard worker who was extremely ambitious.

“A really interesting project where you can, like, really build the player,” Fissette said of Zheng on Tuesday.

It is early days. They are still working to get to know each other and gain the other’s trust. Fissette said the task is a little harder with Zheng because her parents speak only limited English. That has made getting to know more about what makes Zheng tick a little slower, though he said he has learned quickly that she is quite funny, and also loves karaoke. Sometimes she can seem as serious about that as her tennis.

Already though Zheng has begun to adopt some of the trademarks of Fissette’s previous charges, playing with more offense and aggression. She said he often reminds her that players are rarely as aggressive as they think they are. Be the one to dominate the game, he tells her, the champion is almost always the one who is dominating, not the one who is being defensive.

“You can’t just wait for the opponent to miss,” she said.

Twice in this tournament, Zheng has fumbled away one-set leads. She knows why. Her mind begins to drift ahead to the ultimate result instead of focusing on the point she is about to play. Sometimes it takes losing a set to bring her back to the present.

After Wimbledon, where, still struggling to figure out how to play on grass, she lost in the first round, she took a 10-day break and traveled to China to see her extended family, most of whom she had not seen in a year and a half. Her life has had a lot of that.

She loves New York, especially the drive from the Billie Jean King National Tennis Center in Queens back into Manhattan, taking in the view of the skyline. She has spent mornings walking in Central Park, amazed that she can enjoy the quiet of nature in the middle of the metropolis.

“Suddenly all the car noise is gone,” she said.

She is on her own for this trip, without her parents once more. This time, she said, she is embracing the time without them, the chance to make decisions for herself, something she said she still needs to work on. For so long people have been making big decisions for her. Now she is ready to try that for herself.

“I’m at this age, in this moment, when I’ve been feeling quite comfortable on my own,” she said.