NEW YORK — Peng Shuai got so frustrated with her inability to make a serious run at a major title that she nearly quit the sport in 2006, a thought that crossed her mind only once before when she had surgery to repair a heart defect at age 12.
But her day finally came Tuesday when Peng beat 17-year-old Belinda Bencic 6-2, 6-1 in the U.S. Open to earn a spot in a Grand Slam semifinal for the first time in 37 tries. Only five women have participated in more major tournaments before getting to a final four.
"It's an amazing time for me. My coach, my parents, they always tell me to try to keep going and never, ever give up. … Today was coming," said Peng, 28, apologizing as she choked back tears.
She had reached the fourth round of a major tournament five times but had never advanced further in a career dating to 2001. The 39th-ranked Peng becomes the third Chinese player to make a major semifinal after two-time Grand Slam champion Li Na and Zheng Jie, a two-time semifinalist.
Peng next plays 10th-seeded Caroline Wozniacki, a 6-0, 6-1 winner against 13th-seeded Sara Errani.
Peng has not lost a set in the Open. Against Bencic, she hit 24 winners and committed only seven unforced errors.
The 58th-ranked Bencic was the youngest quarterfinalist at Flushing Meadows since Martina Hingis won the title at 16 in 1997. Bencic is coached by Hingis' mother, Melanie Molitor.
Peng said 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 came back to make three Grand Slam fourth rounds in 2011.
Asked why she is doing so well at the U.S. Open now, Peng was at a loss.
"Maybe this time I find a way," she said, "or I catch the right time."
In men's play, Roger Federer, Gael Monfils and Tomas Berdych advanced in straight sets, and Marin Cilic edged Gilles Simon, who was treated for a back problem early, 5-7, 7-6 (7-3), 6-4, 3-6, 6-3.
Monfils was booed when, trailing 40-0 to Grigor Dimitrov in the second set, he halfheartedly flicked a return long. Monfils said he was angry at himself and just wanted to get that game over with. "I was like, 'Just serve, because obviously I give you the game,' " he said.
Monfils next faces Federer, who reached the Open quarterfinals for the 10th time in 11 years by winning the point on 35 of 52 trips to the net against Roberto Bautista Agut.
williams sisters fall: Serena Williams took a medical timeout to have her right ankle re-taped and later double-faulted on the last two points as she and sister Venus lost in the doubles quarterfinals 7-6 (7-5), 6-4 to Ekaterina Makarova and Elena Vesnina. Serena said there was no injury issue. Meanwhile, Hingis reached a Grand Slam doubles semifinal for the first time since 2002 when she and Flavia Pennetta beat Kveta Peschke and Katarina Srebotnik 6-4, 6-3.