Heart and Soul Drives Shuai Peng to Grand Slam Breakthrough

Peng Shuai's soft-spoken demeanour hides a steely resolve that has seen the surprise US Open semi-finalist through some rocky stretches on the road to tennis success.

In her 37th Grand Slam singles appearance, the 28-year-old Peng has at last made it past the fourth round, and will battle on Friday for a place in the US Open final.

She's just 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 double semi-finalist Zheng Jie.

Her success has sparked inevitable comparisons to Li that Peng smilingly 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."

Certainly Peng's earnest remarks, delivered in a genial voice barely above a whisper, could never be confused with the sly wit that has helped make Li a sponsors' darling.

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

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

However, Peng's tennis dream nearly ended when she was 12, when doctors told her a congenital heart defect meant she'd have to quit the sport she'd come to love since she first picked up a racquet four years earlier.

Surgery -- at the youngster's insistence -- solved the problem and after a year to recover she was pursuing her goals again.

A promising first two years as a pro were followed by mediocre results, injuries and disagreement with Chinese authorities on how best to pursue her career.

"I almost stopped playing," she said. "For three or four years it was really tough mentally.

"Then slowly, slowly, slowly ... my team told me to keep going," she said until she began to play the "tennis I dream about."

She reached her highest singles ranking of 14 in the world in 2011, but another spate of injuries followed.

Although her singles career languished, Peng carved out a niche in doubles, winning 16 titles, and in February becoming the first Chinese player to claim a world number one ranking as she topped the doubles chart.

She and longtime doubles partner Hsieh Su-Wei of Taiwan teamed up in the face of rocky relations between their two countries and won their second Grand Slam title at the French Open this year.

The two bowed out in the third round at Flushing Meadows, giving Peng the chance to focus all of her energy on her singles campaign.

She's the only woman apart from five-time champion Serena Williams who hasn't dropped a set in the tournament, and on Tuesday she schooled 17-year-old Belinda Bencic, delivering a barrage of pinpoint passing shots in a a 6-2, 6-1 quarter-final win.

A surprise, yes, but also a reward for Peng's steadfast belief in her own game.

"I dreamed about it," she said of reaching the semis. "Because everybody was asking me all week, maybe you have a chance to get to quarters, so I was really happy to be first time in quarters.

"And I went to the semis. Of course it's exciting, it's a surprise, but it's not like I felt like I could not."