LINZ, Austria (AP) Karin Knapp of Italy advanced to the quarterfinals of the Generali Ladies on Thursday when her opponent Magdalena Rybarikova of Slovakia retired after the opening set with a left leg injury.
After losing the set 6-3, Rybarikova asked for medical treatment but decided to quit the match after briefly speaking to the trainer.
The 59th-ranked Knapp will next play either top-seeded Eugenie Bouchard or Tsvetana Pironkova of Bulgaria.
Anna-Lena Friedsam of Germany advanced to her first career quarterfinal by routing Jana Cepelova of Slovakia 6-0, 6-4.
Friedsam didn't face a break point until serving for the match at 5-3. The 94th-ranked German lost the game before adding another break in the next to close out the win.
Friedsman's next opponent is Stefanie Voegele of Switzerland.