Coco Gauff breezes past Madison Keys to book first trip to US Open last 16

• Gauff wins 6-2, 6-3 to reach fourth round at US Open
• American teen will face China's Zhang Shuai on Sunday

Coco Gauff dominated fellow American Madison Keys to win 6-2, 6-3 on Friday and reach the US Open fourth round for the first time.

The 18-year-old Gauff, who was once again called on to warm up Arthur Ashe Stadium court for Serena Williams ahead of her compatriot's highly-anticipated night match, has now made the second week of all four Grand Slams.