Porsche Tennis Grand Prix defending champion Julia Goerges lost her second round match to Sam Stosur today. Last year, Goerges beat Stosur on her way to the final. German star Andrea Petovic went out today, too, after an ankle twist forced her to retire against Victoria Azarenka. Petkovic had only just returned from a lengthy rehab for a back injury.
Other Germans did better. Mona Barthel defeated 7th seed Marion Bartoli 6-3, 6-1; Barthel beat Ana Ivanovic in the first round. Also advancing to the quarterfinals was Angelique Kerber, who defeated Caroline Wozniacki 6-1, 6-2. Kerber defeated Roberta Vinci in the first round. Wozniacki had advanced to the second round after getting a retirement from Jelena Jankovic, who sustained a back injury.
Akgul Amanmuradova, who upset Dominika Cibulkova in the first round, lost today to Li Na.
Here is the quarterfinal lineup for Stuttgart:
Victoria Azarenka vs. Mona Barthel
Agnieszka Radwanska vs. Li Na
Angelique Kerber vs. Petra Kvitova
Sam Stosur vs. Maria Sharapova