NEW YORK — Yulia Putintseva threw her racket to the ground after dropping the second set, a moment of frustration that became her turning point.
The 35th-ranked player recovered for a 6-3, 2-6, 6-4 victory over No. 8 seed Petra Martic and her first berth in a U.S. Open quarterfinal.
Putintseva has been the best in the women’s bracket at breaking serve, and she converted four of nine chances.
Martic took a medical timeout to get her left foot treated and wrapped before the final game of the match. She finished with 39 unforced errors – 14 more than Putintseva, who will play American Jennifer Brady.
Brady also reached her first U.S. Open quarterfinal by beating Angelique Kerber 6-1, 6-4 in the day’s opening match.