Wednesday
At Armeec Arena
Sofia, Bulgaria
Purse: $750,000
Surface: Hard-Indoor
Round Robin
Singles
Group Serdika
Garbine Muguruza (7), Spain, def. Ekaterina Makarova (1), Russia, 6-2, 6-1.
Standings: Muguruza, 1-0 (2-0); Flavia Pennetta, 1-0 (2-0); Alize Cornet, 0-1 (0-2); Makarova, 0-1 (0-2).
Group Sredets
Andrea Petkovic (4), Germany, def. Tsvetana Pironkova (8), Bulgaria, 7-5, 6-2.
Dominika Cibulkova (2), Slovakia, def. Carla Suarez Navarro (5), Spain, 7-5, 6-4.
Standings: Cibulkova, 2-0 (4-0); Suarez Navarro, 1-1 (2-2); Petkovic, 1-1 (2-2); Pironkova, 0-2 (0-4).