Tournament director Kenneth Low added: "We are certain, however, that Peng will arrive here if she loses in the semi-finals. But if she reaches the final, she will not be able to make it in time for her first-round match."

To be fair, the Hong Kong tournament was probably the last thing on Peng's mind as she reflected on the latest landmark in an often frustrating career after beating 17-year-old Swiss Belinda Bencic 6-2, 6-1.

She will play former world number one Caroline Wozniacki in the semi-finals.

"Thirty-seven times in grand slams," said Peng, who then stopped her train of thought as she struggled to contain her emotions after taking apart Bencic in just 64 minutes.

"It's a little too exciting," she said. "I love tennis, I love to play, but it's a long time, the career. It's tough. Sometimes I've thought about giving up and stop playing because I don't know if I can make it or not.

"My coach and my parents always told me to fight and not give up - that today was coming."

Ranked 39th, Peng has seen off three seeded players to reach the quarters, including fourth-seeded Pole Agnieszka Radwanska. She is the only woman besides two-time defending champion Serena Williams, who has yet to drop a set in a tournament.

Williams and 10th-seeded Wozniacki are the only players remaining from the top 10 seeds.

Peng is the third Chinese player to reach the final four of a major, following in the footsteps of two-time grand slam winner Li Na and doubles semi-finalist Zheng Jie.

Her success has sparked inevitable comparisons to Li, which a smiling Peng does what she can to discourage. "She's one of the really good tennis players because she has a lot of big wins. But everybody is different," said Peng. "She is she and I am me."

Although Peng admitted this week that she felt more pressure from Chinese expectations as Li is absent from the Open with a knee injury, she said that did not mean she was content to toil in her colleague's shadow.

"I never felt like I was in her shadow because I love to play. That's why I continue."

But Peng's dream nearly ended when she was 12. Doctors told her a congenital heart defect meant she would have to quit the sport that she had come to love.

The soft-spoken Peng explained that doctors at one point suggested she should quit the game after heart surgery as a 12-year-old, and she later considered quitting on her own in 2006 after injuries and bad results caused her ranking to slip.

She persevered and came back to make three grand slam fourth rounds in 2011, helping her reach a career-high ranking that year of No. 14. Playing mostly with partner Hsieh Su-Wei, Peng reached a No. 1 ranking in doubles earlier this year.

Asked to explain why she is doing so well at the US Open now, after so many years of falling short, Peng was at a loss.

"Maybe this time I find a way,” she said, “or I catch the right time.”

Meanwhile, Bouchard's fourth-round exit at Flushing Meadows paves the way for her to arrive in Hong Kong early. The Wimbledon finalist was at the centre of a medical drama during her hot and humid match.

She had her blood pressure and temperature monitored in her defeat by Russian Ekaterina Makarova, which raised concerns she would pull out of the Hong Kong tournament.

Bouchard agreed to the event before her remarkable season saw her reach at least the semis of every grand slam until New York.

Low denied speculation of demands for higher appearance fees and delays in announcing her withdrawal over fears it would affect ticket sales.

"This has nothing to do with ticket sales or about having to pay more money for her. We genuinely haven't been able to get in touch with her or her agent. Hopefully, she will turn up on Sunday," Low said.

Additional reporting by Reuters, Agence France-Presse