American Madison Keys overpowered Kaia Kanepi in straight sets to win her quarterfinal tie and complete an all-American line-up in the US Open women's singles semi-finals.
The 15th seed won 6-3 6-3 to join Coco Vandeweghe, Venus Williams and Sloane Stephens in the last four. It is the first time since 1981 that four American women have made the semi-finals in New York, and the first time anywhere since Wimbledon 1985.
Vandeweghe, seeded 20th, beat Czech top seed Karolina Pliskova 7-6 (7-4) 6-3. Williams, 37, is the only one of the four Americans to have reached a Grand Slam final, the first of which came at Flushing Meadows 20 years ago.