Muguruza beats Pennetta at Tournament of Champions

SOFIA, Bulgaria (AP) Garbine Muguruza moved a step closer to the semifinals by beating favorite Flavia Pennetta of Italy 0-6, 6-1, 6-1 in the group stage at the season-ending WTA Tournament of Champions on Thursday.

The Spanish player, who broke serve five times and saved 10 of 13 break points on her own serve, is now the only undefeated player in her Serdika group.

Muguruza will wrap up her round robin schedule on Friday against Alize Cornet of France who stayed alive in her bid for a semifinal spot by defeating top-seeded Ekaterina Makarova of Russia 6-1, 6-4.

Dominika Cibulkova of Slovakia is facing Germany's Andrea Petkovic later on Thursday in the Sredets group.