Vera Zvonareva of Russia hits a shot from the baseline against Michaella Krajicek of the Netherlands in the quarterfinals of the Family Circle Cup tennis tournament in Charleston, South Carolina on April 13, 2007. Zvonareva won the match 6-1, 7-5. (UPI Photo/Nell Redmond)

Zvonareva had little trouble in her 6-2, 6-3 win over Lucie Hradecka in her first match of the clay court tournament. She is to face Magdalena Rybarikova in the round of 16. Rybarikova advanced with a 6-1, 6-3 win over Meghann Shaughnessy.

No. 4-seeded Katarina Srebotnik had the third "double bagel" of her career with a 6-0, 6-0 whitewashing of Yvonne Meusburger and seventh-seeded Klara Zakopalova, a Czech and so a local favorite, rolled with a 6-1, 6-3 win over Sara Errani.

But fifth-seeded Karin Knapp was upset 6-4, 6-2 by Jill Craybas and No. 6-seeded Michaella Krajicek dropped a 6-4, 6-3 decision to Akgul Amanmuradova.

Also winning Tuesday were: Melinda Czink, Karolina Pliskova and Bulgarian Tsvetana Pironkova.

Third-seeded Victoria Azarenka had her opening-round match postponed because of rain.