New York - CoCo Vandeweghe admitted she felt "crummy" after being swept off court by American compatriot Madison Keys 6-1, 6-2 in the US Open semi-finals before weeping at her news conference.
The 25-year-old, playing in her second Slam semi-final of the year after also progressing to the last-four at the Australian Open, was defeated in just 66 minutes.
She hit just nine winners and 22 unforced errors while Keys's figures were 25 and nine.
"It's a pretty crummy feeling right now," she said before brushing away tears with a catch in her voice.
"Madison played an unbelievable match. I didn't really have much to do with anything out there."
Keys will face fellow American Sloane Stephens, who defeated Venus Williams, in Saturday's final.