Lindsay Davenport won the Porsche Grand Prix on Sunday when top-ranked Amelie Mauresmo quit after losing the first set because of an injured left thigh. Davenport captured this No. 1 vs. No. 2 showdown for her tour-high seventh title of the year and 45th of her career. ``It's just a bad feeling -- there's not a whole lot of joy in winning like this,'' Davenport said.