'Philosopher' Petkovic finds her comfort zone

For a woman who admires 19th century philosophy, Andrea Petkovic says she did not need to think at all to reach her first Grand Slam semifinal on Wednesday.

The 20-year-old German credited her thrashing of Italian 10th seed Sara Errani, 6-2, 6-2 at the French Open, to being "in a real zone".

"I didn't think at all. I was just focused on what I had to do. Mentally I was really good," she said.