Wimbledon, England (Sports Network) - Julia Goerges of Germany posted a first- round upset win over Wimbledon runner-up Agnieszka Radwanska at the Olympics on Sunday.

Goerges outlasted Radwanska, the No. 2 seed, by a 7-5, 6-7 (5-7), 6-4 margin at the All England Club.

Rain forced the match to be played under the retractable roof on Centre Court. It was the first time Olympic tennis has been played indoors in the modern era.

Meanwhile, third-seeded Russian Maria Sharapova handled Shahar Peer of Israel 6-2, 6-0 in 65 minutes on Centre Court.

Sharapova won the French Open last month to complete the career Grand Slam. She carried the Russian flag in the opening ceremony.

A shoulder injury forced Sharapova to miss the 2008 Olympics.

Top-seeded Victoria Azarenka's match against Irina-Camelia Begu was postponed because of rain.

The Sports Network