HAMBURG, Germany (AP) _ Fourth-seeded Arantxa Sanchez-Vicario beat fellow Spaniard Magui Serna in straight sets Thursday to reach the quarterfinals of the $535,000 Betty Barclay WTA tournament.

Sanchez-Vicario is making a record 12th appearance in the clay-court tournament, which she has won three times, the last time in 1996.

She beat Serna 6-3, 7-6 and will next play Germany's Andrea Glass, who ousted Tatiana Panova of Russia 7-6 (5), 6-3.

Three other seeded players also moved into the quarterfinals in early action _ No. 6 Anna Kournikova of Russia, No. 7 Anke Huber of Germany and No. 8 Amanda Coetzer of South Africa.

Kournikova overwhelmed Sarah Petkowski of France 6-3, 6-0 and will next challenge top-seeded Martina Hingis, who reached the last eight on Wednesday.

Huber, looking for her second title within a month, extended her unbeaten run on clay this year to 10 by routing Sabine Appelmans of Belgium 6-1, 6-3.

Coetzer also coasted in straight sets, beating Anne-Gaelle Sidot of France 6-1, 6-4.