The all-conquering sisters—practically invincible at Wimbledon since 2000 with a staggering nine titles between them—were dumped out in the last 16 after suffering straight sets defeats.
Defending champion Serena was beaten 6-3, 7-6 (8/6) by French ninth seed Marion Bartoli while big sister Venus lost 6-2, 6-3 to Bulgarian Tsvetana Pironkova for the second year in a row.
“This was definitely not our best day. I think we both envisioned seeing this day going a little bit different,” Venus admitted.
But the Williams sisters rejected suggestions that their double defeat marked the end of an era after a year in which they have both struggled with lengthy injury lay-offs and health problems.
Former world number one Serena, who had not played for nearly a year before returning in the warm-up event at Eastbourne earlier this month, insisted she still had the desire to return to the top.
“I made an effort to get out here and play a couple of tournaments. I just can’t sit here and be disappointed. For the most part, I can just use this as momentum going forward,” she said.
“I can only get better and that can potentially be really scary, because I can only go up from here and I can just do so much more.
“I obviously would have loved to do better but considering the condition I was in, considering a lot of things, I really feel I did well. I would have been sad being at home watching it on TV, like I’m going to be soon.
“I just feel like I can do a lot better, which would really suck if I was here thinking, wow, I played my best and that was the best that I could do.”
Serena’s defeat will see her world ranking drop to around 180th and she may require a wild card to compete at the US Open unless she picks up ranking points during the early part of the hard court season.
Venus, 31, who only returned earlier this month after five months out with a hip injury sustained at the Australian Open, is also confident she will improve by the time the North American hardcourt season climaxes at the US Open.
“I look forward to it. I got ready for this tournament so fast. You wouldn’t even believe how quick that happened,” she said.
“With more time, I think I can definitely play better.