Doha: Top-ranked Caroline Wozniacki beat 2006 champion Nadia Petrova of Russia 6-3, 6-2 Wednesday to reach the quarterfinals of the Qatar Ladies Open.
The Dane joins No. 2 Vera Zvonareva and No. 5 Jelena Jankovic as the remaining seeded players left in the tournament. Zvonareva downed Dominika Cibulkova of Slovakia 6-1, 6-2, and Jankovic defeated Sania Mirza of India 6-0, 6-1.
Wozniacki will play Flavia Pennetta of Italy, who earned a hard-fought 4-6, 6-3, 6-4 win over Lucie Safarova of the Czech Republic.