PARIS -- Grimacing after some poor shots, leaning over with hands on knees while catching her breath after others, Venus Williams left the French Open after the first round for the first time since 2001.
Williams, a seven-time Grand Slam champion seeded 30th, lost 7-6 (5), 6-7 (4), 6-4 Sunday to 40th-ranked Urszula Radwanska of Poland, who never has been past the second round of a major tournament.
The quick exit for the 32-year-old Williams came a year after her younger sister Serena was upset in the first round at Roland Garros.
Radwanska also has a sister who plays professional tennis, Agnieszka, who beat Venus in the second round at the French Open last year.
Venus Williams now has two first-round losses in the past four Grand Slam tournaments.
Serena Williams, meanwhile, returned Sunday to the red clay of the French Open, and this time there was no stumble at the start.
Upset in the first round a year ago, Williams channeled any lingering frustration into her overpowering strokes and drubbed Anna Tatishvili 6-0, 6-1.
Also advancing from the first round was Roger Federer, who swept qualifier Pablo Carreno Busta 6-2, 6-2, 6-3 on Sunday.
Playing at Roland Garros for the 15th year in a row, Federer earned a big roar from the center court crowd after he closed out the victory with a picturesque backhand winner. Federer lost only seven points on his first serve and was broken just once.
The 21-year-old Spaniard was making his Grand Slam debut after winning seven consecutive Futures events.
Federer, the 2009 champion, remained unbeaten in first-round matches at major tournaments since 2003.
Williams lost her opening match at a Grand Slam tournament for the only time in her career a year ago, when she was beaten by France's Virginie Razzano. That was the most surprising in a succession of losses for Williams at Roland Garros, where she hasn't won the title since 2002 and hasn't reached the semifinals since 2003.
Determined to avoid another bad start, Williams won the first nine games, and 30 of the first 37 points. There was no letup from there, and she was still pumping her fist and shouting "Come on!" a game from the finish.
Williams maintained a stern expression throughout the match, and allowed herself only a brief smile when Tatishvili pushed a forehand wide on match point.
Williams, who keeps an apartment in Paris, was then interviewed on center court and spoke French, a first for her at Roland Garros.
"I'm a beginner," she said, referring to her French, not her tennis. "I think I am French because I have a flat here. I love Paris."
Williams won 56 of 78 points, including 28 of 33 on her serve, and hit eight aces.
She'll face tougher competition in the rounds to come -- Tatishvili fell to 2-11 this year and 0-3 at the French Open.
Play began under cloudy skies with the temperature in the mid-50s (13 C), and an hour into the tournament, Errani was into the second round. The tenacious Italian beat Arantxa Rus 6-1, 6-2 in the opening match on Court Suzanne Lenglen.
Errani reached a Grand Slam final for the first time a year ago at Roland Garros.
"Last year was an unbelievable tournament, the best tournament of my life," Errani said. "But I don't want to think about that. I just want to come here and play another tournament. I try to concentrate on my tennis, not too much about last year."
Now ranked a career-best No. 5, Errani dominated Rus from the baseline and won four games at love. Rus double-faulted seven times and lost her 13th consecutive match on the WTA Tour.
Ivanovic, seeded 14th, beat Petra Martic 6-1, 3-6, 6-3. Ivanovic improved to 30-4 in the first round of Grand Slam tournaments.