Sharapova ousts Radwanska to reach Porsche semis

Stuttgart, Germany ( - Two-time defending champion Maria Sharapova straight-setted top seed Agnieszka Radwanska in Friday's marquee quarterfinal at the $710,000 Porsche Tennis Grand Prix.

The sixth-seeded former world No. 1 star whipped her Polish counterpart 6-4, 6-3 on the indoor red clay at Porsche Arena.

Sharapova needed a whopping eight match points to finally put Radwanska away.

"This was a big victory for me, the biggest since my injury," said Sharapova, who returned late last season after missing more than four months following shoulder surgery.

The tall Russian is now a dominant 9-2 lifetime against the former Wimbledon runner-up Radwanska, including a flawless 3-0 mark on clay.

Sharapova beat Chinese stalwart Li Na in last year's marquee Porsche finale. Her semifinal opponent on Saturday will be eighth-seeded Italian Sara Errani, who was leading Carla Suarez Navarro 6-3, 6-7 (6-8), 3-0 when the nifty Spaniard retired on Day 5 due to a hand injury.

Sharapova and Errani will meet in a rematch of the 2012 French Open final, which was won easily by last year's Roland Garros runner-up from Russia. Sharapova is a perfect 4-0 lifetime against the gritty Italian.

Meanwhile, fifth-seeded former No. 1 Jelena Jankovic handled Russian Alisa Kleybanova 6-4, 6-3 and a battle of former French Open champs saw ninth- seeded former top-ranked star Ana Ivanovic outlast two-time Grand Slam winner Svetlana Kuznetsova 6-3, 2-6, 6-4.

The Russian veteran Kuznetsova captured this Porsche event back in 2009.

The 2009 Porsche titlist Jankovic and Ivanovic will clash in an all-Serbian semi on Saturday. Ivanovic leads the lifetime series 8-3, including wins in the last two meetings.

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