By Larry Fine
NEW YORK (Reuters) - China's Zhang Shuai, who broke through with a stunning run to this year's Australian Open quarter-finals, advanced to the third round at the U.S. Open on Thursday with a victory over former champion Samantha Stosur.
Zhang lost serve just once in ousting the 16th-seeded Australian 6-3 6-3 on the Grandstand court.
The 51st-ranked Zhang became the first women's qualifier since 1990 to reach the quarters in Melbourne, in a surprise charge that came after she had failed to get past the first round of 14 successive majors dating back eight years.
Against 2011 U.S. Open winner Stosur, who reached the semi-finals at this year's French Open, Zhang won a baseline battle by outmanoeuvring the Australian, forcing her into 27 errors, including 20 from the forehand side.
Zhang next faces 52nd-ranked Yaroslava Shvedova of Kazakhstan, who routed China's Wang Qiang 6-0 6-1.
(Editing by Andrew Both)