Instead of looking forward to playing each other this week at the French Open, Serena and Venus Williams will both be heading home early.
The American sisters both lost in the second round, each being outplayed by little known opponents at Roland Garros.
Serena, the defending French Open champion and a 17-time major winner, lost to Garbine Muguruza of Spain 6-2, 6-2, while older sister Venus was eliminated by Anna Schmiedlova of Slovakia 2-6, 6-3, 6-4.
The Williams siblings would have met in the third round had they both won.
"It was one of those days. You can't be on every day, and, gosh, I hate to be off during a Grand Slam,'' Serena said. "It happens, you know. It's not the end of the world. It is what it is.''
Serena struggled from the start against the 20-year-old Muguruza and finished the match with only eight winners and 29 unforced errors.
Muguruza was playing at the French Open for only the second time in her career.
She lost in the second round last year, but reached the fourth round at the Australian Open in January.
Venus loses concentration
Venus Williams' loss was the eighth time in her last nine major tournaments that she has failed to win more than one match.
The seven-time Grand Slam champion won the first set and was up an early break in the second. But the 19-year-old Schmiedlova responded by taking eight of nine games and won 2-6, 6-3, 6-4.
Against Schmiedlova, the 29th-seeded Williams ended up with 47 unforced errors while Schmiedlova had only 20.
Venus Williams has never won the French Open, but lost to Serena in the 2002 final in their only meeting at Roland Garros.
Djokovic maintains form
Avoiding the sort of surprise this French Open has been producing, second-seeded Novak Djokovic moved into the third round with a 6-1, 6-4, 6-2 victory over 42nd-ranked Jeremy Chardy.
Owner of six major trophies but never the champion at Roland Garros, Djokovic is trying to become the eighth man to complete a career Grand Slam.
He's been to the semifinals five of the past seven years in Paris, losing to Rafael Nadal in the 2012 final.
Djokovic needed only 1.5 hours to eliminate Chardy and improve to 9-0 against the Frenchman.