Cibulkova improved her record to 3-0 against Suarez Navarro, who had not won a match in seven tournaments before beating Kateryna Bondarenko here in the first round.

Seventh-seeded Agnieszka Radwanska also reached the final eight by beating Elina Svitolina of Ukraine 6-4, 6-1 and will play Karolina Pliskova of the Czech Republic, who eliminated the last remaining Japanese player by defeating Kurumi Nara 6-2, 6-4.

The 11th-ranked Pliskova served 10 aces and rallied from 4-1 down in the second set to clinch the match.