SEOUL -- Top-seeded Russian Nadia Petrova was a second-round winner Thursday at the Korea Open, but the next three seeds were all eliminated.
Petrova rolled to a 6-3, 6-4 victory over American Vania King, but Russians Anastasia Pavlyuchenkova and Maria Kirilenko, as well as Spain's Maria Jose Martinez Sanchez were each sent packing in straight sets.
Defending champion Kimiko Date Krumm of Japan upended the second-seeded Pavlyuchenkova, 6-2, 6-1, while former world No. 1 Dinara Safina of Russia knocked off the third-seeded Kirilenko, 6-2, 6-3, and Russian Ekaterina Makarova dumped the fourth-seeded Martinez Sanchez, 6-4, 7-5.
Other seeded winners Thursday were Russia's Alisa Kleybanova and Hungary's Agnes Szavay, while Belgium's Kirsten Flipkens and Klara Zakopalova of the Czech Republic also advanced with victories.
Kleybanova, the fifth seed, dropped an epic first-set tiebreaker before rolling over fellow Russian Ksenia Pervak, earning a 6-7 (13-15), 6-1, 6-2 triumph to set up a quarterfinal matchup with Makarova. The eighth-seeded Szavay posted a 6-3, 7-5 win over Britain's Elena Baltacha and will next meet Date Krumm.
Flipkens upset sixth-seeded Yaroslava Shvedova of Kazakhstan, 6-4, 6-1, and will square off against the top-seeded Petrova in the quarterfinals, while Zakopalova defeated Russian Vera Dushevina, 6-4, 7-6 (7-5) and will tangle with Safina in the quarters.