After four days of play, the French Open was left without a Williams sister in the draw on Wednesday when former runner-up Venus joined 2002 champion Serena in making an early exit.
Venus, seven times a grand-slam winner but now coping with an autoimmune disease, went out tamely 6-2 6-3 to third seed Agnieszka Radwanska.
Serena, whose shock first-round defeat by Frenchwoman Virginie Razzano reverberated through the Roland Garros courts on Tuesday, was in the stands to see her big sister thrashed by an in-form Radwanska.
Tennis fans rued the loss of both Americans, two of the biggest characters in women's tennis, but thankfully the men's favourites are playing to form and both world number one Novak Djokovic and record-breaking 2009 champion Roger Federer survived into the third round.
At least one of the Williams sisters has featured at every French Open since 1997, except for last year when they were both injured, and they contested the final in 2002, with Serena winning.
As though in sympathy with their troubles this year, rain came to Paris after three days of glorious sunshine, and play ended early with fifth-seeded Frenchman Jo-Wilfried Tsonga level at 6-2 4-6 1-1 with German Cedric Marcel Stebe on Suzanne Lenglen court.
Venus showed flashes of her old self only at the end of the hour-long match with Radwanska when she won to love for 5-2 and then broke her opponent.
However, Radwanska, covering the whole court and playing some sublime shots, scooped the ball over the American's head to get to matchpoint in the following game and then watched Venus put a forehand out.
Venus was quiet but determined not to be downcast in her news conference, saying she was still learning to live with Sjogren's Syndrome.
"There are a lot of people who have it a lot worse than I do. I am still playing a professional sport," the former world number one said.
"I haven't gotten to the 'why me?' yet, I hope I never get to the 'why me?' I am not allowed to feel sorry for myself."
The women's draw also lost eighth-seeded local favourite Marion Bartoli, a semi-finalist here last year, who was beaten 6-2 3-6 6-3 by world number 50 Petra Martic of Croatia.
World number one Victoria Azarenka, however, redeemed herself after nearly losing in the first round when she easily beat German qualifier Dinah Pfizenmaier 6-1 6-1.
Federer and Djokovic both made hard work of the second round for themselves.
The Swiss collected a record-breaking 234th grand-slam match win but only after squandering two matchpoints in a third-set tiebreak and having to stay out for a fourth set against Romanian Adrian Ungur.
Federer eventually won 6-3 6-2 6-7 6-3 to pass the winning record of American Jimmy Connors, which he had equalled in the first round, and chided himself for being too passive in the tiebreak.
"Instead of being aggressive, I let him show me what he could do," said the third seed, who will now play Frenchman Nicolas Mahut.
World number one Djokovic, needing only the title here to become the first man in 43 years to hold all four grand-slam crowns at the same time, won the first seven games against entertaining Slovenian Blaz Kavcic but then, in his own word, "stopped".
"I gave him the opportunity to come back into the match after a perfect first seven games," said the Serbian who won 6-0 6-4 6-4 in the end, despite the crowd getting firmly behind underdog Kavcic.
Argentine clay specialist Juan Martin del Potro, the ninth seed, set up a third-round match with Croatian Marin Cilic - a difficult opponent in his opinion - by beating France's Edouard Roger-Vasselin 6-7 7-6 6-4 6-4, while 11th seed Gilles Simon also won through.
U.S. Open women's champion Samantha Stosur, the runner-up here in 2010, defeated American Irina Falconi 6-1 6-4 and will now play 27th-seeded Russian Nadia Petrova.
Ana Ivanovic, on the comeback trail after her career took a dive following her 2008 win at Roland Garros, enjoyed a 6-2 6-2 win over Israel's Shahar Peer.
The next opponent for the 13th-seeded Serbian, who said she hungered for more success, will be Italian Sara Errani, seeded 21.