Top seed CoCo Vandeweghe marched into the Libema Open quarter-finals with a 7-6(4) 6-3 win over Arantxa Rus in the second round on Wednesday.
American Vandeweghe, a quarter-finalist at Wimbledon last year, is on course to win her third title at Hertogenbosch after a commanding performance during which she hit 26 winners, including 11 aces, to dismantle Rus's challenge in a little over 90 minutes.
World number 16 Vandeweghe will take on the winner of the match between American Alison Riske or Hungarian qualifier Fanny Stollar in the last eight.
Russian Veronika Kudermetova, who stunned defending champion Anett Kontaveit in the first round, reached her first WTA quarter-final after ousting Switzerland's Belinda Bencic 6-2 2-6 6-3.
The 21-year-old will face Serbian Aleksandra Krunic in the last eight after the seventh seed eased to a 7-5 6-2 win over Bibiane Schoofs of the Netherlands.