Kvitova ousted; Ivanovic wins Porsche opener

Stuttgart, Germany ( - Former Wimbledon champion Petra Kvitova suffered a second-round upset, while former world No. 1 star Ana Ivanovic was an easy opening-round winner Wednesday at the $710,000 Porsche Tennis Grand Prix.

Russian Alisa Kleybanova reached the quarterfinals by dousing the third-seeded Czech left-hander Kvitova in 6-2, 7-6 (7-3) fashion, while the ninth-seeded former French Open champion Ivanovic whipped last year's Wimbledon runner-up Sabine Lisicki, of Germany, 6-1, 6-3 on the indoor red clay at Porsche Arena.

In other second-round action on Day 3 in Stuttgart, eighth-seeded former French Open runner-up Sara Errani subdued Estonian Kaia Kanepi 6-3, 6-3.

And in other opening-round play, Italian Flavia Pennetta held off wild card and German favorite Andrea Petkovic 7-5, 3-6, 6-1 and another German wild card, Julia Goerges, topped Romanian Sorana Cirstea 6-1, 7-5. Goerges was the Stuttgart champ in 2011.

Several stars will see action on Thursday, as top-seeded Pole Agnieszka Radwanska will face Italian Roberta Vinci; second-seeded Romanian Simona Halep will encounter two-time Grand Slam champion and 2009 Stuttgart champion Svetlana Kuznetsova; fourth-seeded German star Angelique Kerber will meet Spaniard Carla Suarez Navarro; fifth-seeded former world No. 1 and 2008 winner Jelena Jankovic will clash with Pennetta; sixth-seeded former top-ranked star and two-time defending champion Maria Sharapova will be opposed by fellow Russian Anastasia Pavlyuchenkova; and Ivanovic will tangle with Goerges. No less than three former No. 1s will take to the courts on Day 4.

Sharapova beat Li Na in last year's marquee finale.

The 2014 Stuttgart champ will claim $135,000 and a Porsche 911 Carrera sports car.