Top seed Nicole Vaidisova and second seed Anna-Lena Groenefeld both crashed out of the Cellular South Cup Tuesday.

World No. 13 Vaidisova, of the Czech Republic, suffered a stunning first-round loss to Belarussian wild card Victoria Azarenka, 7-6(5), 2-6, 6-4.

Azarenka, at just 16, had won just one WTA-level match this year before Memphis. She defeated Amy Frazier in the first round of Auckland. She won three qualifying matches at the Australian Open but then fell in the first round of the main draw to rising Indian star Sania Mirza.

World No. 22 Groenefeld, who enjoyed a comfortable first-round win Monday, bowed out of the tournament Tuesday with a 7-6(5), 6-2 win over Shenay Perry.

Fifteen-year-old Dane Caroline Wozniacki reached the quarterfinals with a 6-2, 6-3 win over American Ashley Harkleorad.