Serena Williams in action against Tzipora Obziler in Bangalore on Wednesday. (AP)

Bangalore: World No. 11 Serena Williams beat Israeli Tzipora Obziler 7-5, 6-0 at the Bangalore Open on Wednesday.

The former world No. 1 advanced to the quarter finals but was far from her dominant self in the opening set of her second-round victory.

Fourth seeded Patty Schnyder of Switzerland also moved into the quarter finals with a 6-7, 6-4, 6-2 victory over Japan’s Aiko Nakamura.

Serena had trouble with her service games early on against 117th-ranked Obziler.

“I started making so many errors and the balls kept flying about there,” Serena told a news conference.

Serena will meet Anastasia Rodionova, who beat sixth seed Austrian Sybille Bammer 7-6, 6-2 in the second round.

In the day’s other upset, Uzbek Akgul Amanmuradova beat fifth-seeded Hungarian Agnes Szavay 4-6, 7-6, 6-4.