Simona Halep is the No. 2 seed at the United States Open, and she entered her round of 16 match with more hardcourt victories this year than any other woman in the main draw, having compiled a 35-5 record.
But she had never reached the Open quarterfinals until Monday, when she escaped with a 6-7 (6), 7-5, 6-2 victory over 24th-seeded Sabine Lisicki.
Like Halep, Petra Kvitova, a two-time Wimbledon champion, had been among the final eight at the other three majors but had never found much fortune once the U.S. Open rolled around.