NEW YORK - Madison Keys completed a clean sweep for American women on Wednesday, giving the host country all four US Open semifinal spots for the first time in 36 years.

The 15th-seeded Keys served impeccably, controlled groundstroke exchanges from the baseline and was never in trouble en route to a 6-3, 6-3 victory over 418th-ranked qualifier Kaia Kanepi of Estonia that took just 69 minutes.

It came several hours after 20th-seeded CoCo Vandeweghe's 7-6(4), 6-3 elimination of 2016 runner-up and top-seeded Karolina Pliskova of the Czech Republic.