Teenager Coco Gauff reached the quarter-finals of the US Open for the first time on Sunday with a 7-5, 7-5 victory over China's Zhang Shuai.
The 18-year-old 12th seed from Atlanta advanced to a last eight meeting with France's Caroline Garcia after prevailing in 1hr 57minutes.
Prior to this season, Gauff had never gone further than the third round at the US Open.
Gauff, who reached the final of the French Open in June, was forced to work hard for her victory against the skillful Chinese veteran Zhang.
The 33-year-old from Tianjin paid the price however for a lack of composure at key moments.
Gauff broke the Chinese world number 36 to take a 6-5 lead in the first before holding to clinch the first set.
Zhang then squandered a golden chance to level in the second set when she broke Gauff to leave herself serving for the set at 5-3.
Gauff however rallied to reel off four straight games, breaking Zhang twice to seal victory and advance to the quarter-finals.