Jennifer Capriati showed superb defensive skills, running down powerful, angled shots from Serena Williams and eventually drawing enough unforced errors to make their quarterfinal match close Tuesday night, but had the chair umpire and line judges not made four bad calls against Serena in the final set, Capriati's 2-6, 6-4, 6-4 win would have been unlikely. Particularly horrible was the chair umpire's call in the first game of the set, giving Capriati the point after Serena hit a winner that was clearly in and called good by the line judge. It seemed that that chair umpire had made a scoring error at first, but apparently she overruled the line judge's call despite its being on the far sideline from the chair. An overrule should only be made on a blatant error from the line judge, and in this case, the line judge's call was obviously correct. Serena protested in vain, then lost the game, giving Capriati the break. Serena showed admirable composure through the rest of the set, which ended with a tight game in which she received three more bad calls. Capriati played a smart match, using her slice backhand to great effect as the match progressed.