Early action Thursday was filled with upsets as five of the Top 8 seeds fell in their Round of 16 matches.
Top seed and defending champion Jelena Jankovic lost her Round of 16 match to qualifier Akgul Amanmuradova. Amanmuradova is the first qualifier to reach the quarterfinals since she advanced to the semifinals in 2007.
Amanmuradova will meet Ana Ivanovic who became the first woman to advance to the quarterfinals by winning her third straight match against a higher ranked opponent. Ivanovic rolled past German Elena Vesnina 6-0, 6-3.
No. 2 seed Caroline Wozniacki , who dispatched of Sybille Bammer in just 51 minutes the day before, fell to No. 16 seed Marion Bartoli 6-4, 6-0. Bartoli will play Maria Sharapova who continued her dominant performance in Cincinnati with a victory over No. 7 seed Agnieszka Radwanska 6-4, 6-2.
Italian Flavia Pennetta, a semifinalist last year, upset No. 6 seed Vera Zvonareva 6-4, 6-3. Pennetta, the No. 11 seed, will play No. 4 seed Kim Clijsters who rolled in the night match against American wild card Christina Mchale 6-1, 6-1. Mchale's departure means that no Americans remain in the main draw.
In an upset laden year, Clijsters is the only player remaining from the Top 9 and the only member of the WTA Top 10 still alive in the tournament.
No. 12 Yanina Wickmayer completed the early sweep of Top 8 seeds by defeating No. 8 seed Na Li in a thrilling three set match, 2-6, 6-2, 7-6(4). Wickmayer awaits the winner of No. 13 seed Shahar Peer and Anastasia Pavlyuchenkova.