Defending champion Naomi Osaka overwhelmed 15-year-old Coco Gauff to reach the US Open last 16 in front of a captivated Arthur Ashe Stadium.
World number one Osaka, 21, won 6-3 6-0 against the home favourite - and later consoled the emotional American in heart-warming scenes.
Gauff matched Osaka for much of the first set, but her game - particularly serve - unravelled in the second.
She produced double faults at crucial times as Osaka broke serve six times.
Osaka, who added the Australian Open title to her maiden major win here last year, will face Swiss 13th seed Belinda Bencic in the fourth round.