On the night that she debuted her new service motion, it was Gauff's tennis foundations that propelled her to victory.

Coco Gauff is moving on at the U.S. Open, but it was far from easy. The third-seeded American battled her way to a, 6-4, 6-7 (7), 7-5 win over Australia’s Ajla Tomljanovic at Arthur Ashe Stadium on Tuesday night. She had 10 double faults but broke Tomljanovic eight times, including late in the third set to avoid the upset.