Cibulkova, Navarro, Pennetta win in straight sets

SOFIA, Bulgaria (AP) Dominika Cibulkova, Carla Suarez Navarro and Flavia Pennetta were straight-sets winners at the start of the season-ending WTA Tournament of Champions on Tuesday.

Second-seeded Cibulkova of Slovakia defeated Tsvetana Pironkova of Bulgaria 6-3, 7-6 (6) in round robin play in the Sredets group. In the group's other match Spain's Navarro overcame fourth-seeded Andrea Petkovic of Germany 6-0, 6-4.

In the Serdika group opener, Italy's Flavia Penetta, seeded third, easily beat Alize Cornet of France 6-1, 6-2.

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