American teenage sensation Coco Gauff has set up a third-round showdown with defending champion Naomi Osaka at the US Open.
The 15-year-old survived a second-round thriller with Hungarian Timea Babos to win 6-2, 4-6, 6-4 at Louis Armstrong Stadium on Thursday night.
"This is just the beginning, I promise," Gauff told the crowd.
Meanwhile, unseeded American Taylor Townsend upset Wimbledon champion and No. 4 seed Simona Halep in the second round with a 2-6, 6-3, 7-6 (7-4) win.