Hingis overwhelmed Tatiana Panova of Russia, 6-1, 6-2, as she sought her third straight Porsche Tennis Grand Prix title and fifth overall.
Capriati fell in her first quarterfinals appearance here in five attempts. The American suffered second-round exits in 1996 and
1999 and first-round eliminations in 1997 and 2000.
By contrast, Testud won the 1998 Filderstadt title and reached the semifinals the following year.
The winner of this year's Australian and French Opens, Capriati lost to Testud for the first time in three meetings in 2001. The 25-year-old handled Testud in straight sets in the round of 16
at the German Open claycourt event in May and Wimbledon in July.
Henin of Belgium rallied after dropping the first set to edgeAnke Huber of Germany, 6-7 (4-7), 6-2, 7-5.