NEW YORK (AP) 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.
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.
''My coach, my parents, they always tell me to try to keep going and never, ever give up,'' said the 28-year-old Peng.
Before her run at Flushing Meadows, she had reached the fourth round of a major tournament five times but had never advanced further in a career going back 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 has not lost a set and kept up that consistency against Bencic, hitting 24 winners and committing only seven unforced errors. Her young opponent, meanwhile, appeared to become unglued in the muggy, 92-degree heat of Arthur Ashe Stadium.
The 58th-ranked Bencic was the youngest quarterfinalist at Flushing Meadows since her mentor, Martina Hingis, won the title at 16 in 1997. Bencic is coached by Hingis' mother, Melanie Molitor.
The Swiss teen was issued a code violation for receiving help from her box while down 2-0 in the second set.
''It's 6-2, 2-0 and you're giving me a code violation?'' Bencic yelled at the chair umpire.
She went on to lose that game to go down 3-0.
''It was a little bit tough,'' Bencic said later, ''but I think it was (an) awesome tournament for me.''
Peng next plays 10th-seeded Caroline Wozniacki, a 6-0, 6-1 winner against 13th-seeded Sara Errani in Tuesday's last match.
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-round appearances in 2011, helping her reach a career-high ranking that year of No. 14. Playing mostly with partner Hsieh Su-Wei, Peng reached the No. 1 ranking in doubles this year.
Asked to explain why she is doing so well at the U.S. 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.''