Qualifier Kiki Bertens advanced to the quarterfinals of the clay-court tournament in Nuremberg by beating top-seeded Roberta Vinci 6-4, 7-6 (4) Wednesday.

Vinci was last year's runner-up at the tournament, which serves as a warm-up for the French Open.

Fifth-seeded Sabine Lisicki had six double-faults and was also eliminated, losing to Varvara Lepchenko 6-2, 7-6 (5).