Rain sent Olympic tennis indoors for the first time in 100 years Sunday, when Julia Goerges of Germany upset No. 2-seeded Agnieszka Radwanska of Poland in the first round under Wimbledon's retractable roof.
The No. 24-ranked Goerges, making her Olympic debut, hit 20 aces to beat this year's Wimbledon runner-up, 7-5, 6-7 (5), 6-4.
Showers delayed the start of play and prompted tournament officials to close the Centre Court roof for the match, which began only five minutes late. Action on 11 uncovered courts began after a delay of nearly three hours, then was interrupted by more rain.
The indoor match was the first in the Olympics since the 1912 Games in Stockholm, played in a pavilion on wood courts painted black.
''I didn't really think about it as it's my first time on the Centre Court, and you just go there and enjoy it,'' Goerges said. ''You just play there as you warmed up outside. The courts were different. But that's, for both, the same.''
No. 3-seeded Andy Murray of Britain returned to the court where he lost this month's Wimbledon final and beat Stanislas Wawrinka of Switzerland under the roof, 6-3, 6-3.
Murray also defeated Wawrinka in the first full match under the roof, played at Wimbledon in 2009. Murray lost the Wimbledon final three weeks ago to Roger Federer.
Ten matches were postponed because of rain, including first-round doubles matches involving the 2008 gold medal teams, the Williams sisters and Federer-Wawrinka.
Goerges and Radwanska endured some sloppy moments in the early going before they adjusted to the slow indoor conditions. At one point, rain on the roof fell so heavily it was difficult to hear the ball being struck.
Goerges' serve kept her in the match, and she also moved forward effectively, winning 19 of 24 points at the net.
''I felt pretty great there,'' Goerges said. ''My game is to be aggressive, and I know that doesn't suit her pretty well because she's one who wants to create a little bit of angles to play clever on the court.''
In the final set she hit a deft drop shot to hold for a 5-4 lead, then broke serve in the last game, whacking a return winner on the first match point.
That ended medal hopes in singles for Radwanska, who is playing doubles with her sister. Less than four weeks ago, Radwanska became the first Polish player to reach a Grand Slam final since 1939, then lost to Serena Williams.
