After putting up a double bagel Tuesday to advance to the second round of the 2013 U.S. Open, the fourth-seeded women's singles player, Sara Errani, fell to fellow Italian Flavia Pennetta, 6-3, 6-1, on Thursday.
Pennetta recorded seven aces overall as Errani, who made last year's semifinals in the event, couldn't produce one. Pennetta has made the U.S. Open quarterfinals three times in her career and on Thursday won 6-of-7 break points and 28-of-45 receiving points to drop her fellow countrywoman.
In the top half of the tournament bracket, No. 9 seed Jelena Jankovic of Serbia cruised past Russia's Alisa Kleybanova, 6-3, 6-2. Jankovic's victory sets her up to face Kurumi Nara of Japan, who upset No. 19 seed Sorana Cirstea.
Also in Thursday's early action, 16th-seeded Sabine Lisicki of Germany beat Argentina's Paula Ormaechea, 6-2, 6-3. Lisicki will face No. 24 seed Ekaterina Makarova in the third round. Makarova beat American Bethanie Mattek-Sands on Thursday, 6-4, 6-4.
Top seed and reigning U.S. Open champion Serena Williams will face Kazakhstan's Galina Voskoboeva later Thursday and the winner will face Voskoboeva's fellow countrywoman, Yaroslava Shvedova, in the third round. Shvedova defeated Patricia Mayr-Achleitner of Austria in the second round.