"I can't really serve very hard. It's painful when I do that. But I'm getting better. I just, you know, ran out of time to get better for this tournament," said Williams, broken 11 of the 17 times she served Sunday. "My strategy was more or less to put the ball in, and that's very difficult for me, too, because that's not who I am. But that's all I had."
Her quick exit came a year after she lost in the second round at Roland Garros to Radwanska's older sister, Agnieszka, the 2012 Wimbledon runner-up.
"Yeah, of course, I was talking with Aga about Venus," Urszula said. "I was well-prepared for this match, and I knew she was a great fighter, so I should be focused the whole match."
Williams, 32, also knows a thing or two about having a more successful tennis-playing sibling, and her short stay in Paris comes a year after younger sister Serena, who owns 15 Grand Slam titles, was upset in the first round at Roland Garros by 111th-ranked Virginie Razzano. Serena made a triumphant return to the clay-court tournament in the early afternoon Sunday, overwhelming 74th-ranked Anna Tatishvili 6-0, 6-1.
The only other seeded player to lose on Day 1 was No. 11 Nadia Petrova of Russia, who was defeated by Monica Puig of Puerto Rico 3-6, 7-5, 6-4. Otherwise, results went to form, with 17-time major champion Roger Federer picking up a 6-2, 6-2, 6-3 victory over a guy making his Grand Slam debut, Pablo Carreno Busta of Spain, while No. 4 David Ferrer, No. 14 Milos Raonic of Canada and No. 18 Sam Querrey of the United States also were among the winners.
In an intriguing encounter filled with momentum swings, No. 15 Gilles Simon of France overcame a two-set deficit for the first time in his career to edge two-time major champion Lleyton Hewitt 3-6, 1-6, 6-4, 6-1, 7-5.
P Monday, 3 a.m., ESPN2; noon, Ch. 5