The difficulties continued for Daniela Hantuchova and Anna Chakvetadze as both players were upset in the Pacific Open.

The seventh-seeded Hantuchova was defeated 6-1 7-5 by Italy's Francesca Schiavone while Chakvetadze, the eighth seed, lost 6-4 3-6 6-3 to Estonian qualifier Kaia Kanepi.

Sixth seed Agnieszka Radwanska posted a decisive 6-1 6-4 victory over wild card Aiko Nakamura of Japan in their first-round match.

Radwanska, the world number 10, will next face Marion Bartoli, who also had little trouble advancing. The Frenchwoman posted a 6-2 6-2 win over Russian Maria Kirilenko.

Bartoli won 85% (17 of 20) of first-serve points and was perfect on break chances, converting all five in the match.

Wild card Ayumi Morita of Japan took advantage of 12 double faults by Hungary's Agnes Szavay to claim a thrilling 6-7 (7/9) 7-5 6-4 triumph.

Dominika Cibulkova overcame a dismal first set to post a 0-6 6-1 7-6 (10/8) victory against wild card Amelie Mauresmo.

Cibulkova won only 12 of 38 points in the first set. The Slovakian bounced back in the second set, converting a pair of break points while taking advantage of five double faults by Mauresmo. Cibulkova outlasted Mauresmo in the third-set tie-break to improve to 2-0 lifetime against the Frenchwoman.

Mauresmo's compatriot Alize Cornet needed three sets to come away with a victory, posting a 4-6 6-3 6-3 win over Canadian qualifier Aleksandra Wozniak.

Flavia Pennetta also progressed with a 6-4 6-4 win over Shahar Peer and will face top seed and US Open finalist Jelena Jankovic of Serbia in the second round.