LINZ, Austria (AP) Fourth-seeded Carla Suarez Navarro reached the quarterfinals of the Generali Ladies by defeating fellow Spaniard Sara Sorribes Tormo 6-4, 6-1 on Wednesday.
Suarez Navarro will next play Denisa Allertova of the Czech Republic, who beat Anett Kontaveit of Estonia 6-3, 6-4.
The 12th-ranked Suarez Navarro led 5-1 but struggled to close out the opening set against Sorribes Tormo before dominating the second.
''If you play against a friend it's always difficult,'' Suarez Navarro said. ''In the second set I was really solid.''
French qualifier Oceane Dodin also reached the quarterfinals by beating Sorana Cirstea of Romania 6-2, 6-4. The 89th-ranked Dodin, who won her maiden title in Quebec last month, had eight aces and avoided break points on her serve.
Earlier, French Open champion Garbine Muguruza beat Cagla Buyukakcay of Turkey 6-4, 6-4 in a first-round match.
The top-seeded Spaniard dropped serve twice and saved six more break points as she struggled for consistency against the 69th-ranked Buyukakcay.
''On this surface it was very difficult for me,'' Muguruza said. ''It's my first indoor event so it's hard to find your rhythm.''
Muguruza, who was a late entry to the event after U.S. Open finalist Karolina Pliskova pulled out, will next play Monica Niculescu of Romania.
In other first-round play, Dominika Cibulkova beat Belinda Bencic of Switzerland 6-1, 6-2. The 10th-ranked Slovak, who reached the final in 2011, converted all six break points while Bencic managed to hold her serve only once in the match.
Cibulkova will play Annika Beck of Germany for a place in the quarterfinals.
Also, third-seeded Madison Keys of the United States defeated Camila Giorgi of Italy 6-3, 6-4, and Kirsten Flipkens advanced after Mandy Minella of Luxembourg pulled out with a hip injury after the Belgian won the opening set 6-4.