Since their late teens, Serena and Venus Williams have both made their mark at the greatest—and only—sisterhood to dominate women's tennis for the past 18 years. Together, the Williams sisters were the indomitable force that no women's double partnership could even think of besting for a W in the Olympics. Now in the twilight of their careers, and well into their 30s, they finally faltered today as doubles partners for the first time since they competed in their initial Olympic Games in 2000.

The Williams sisters were eliminated from the first round (double-take that is was not in their familiar place of a championship round) by Czech team of Lucie Safarova and Barbora Strycova 6-3, 6-4 in Rio after 93 minutes of play. Safarova and Strycova proved to be strong competition because they are both ranked in the top-30 as singles players.

The Williams were returning as doubles partners after a two-year break from competing together. Before being defeated on Sunday, the Compton, Calif. natives had a 15-0 tennis double run as doubles partners in the Olympic Games, and won gold medals in women's doubles in 2000, 2008, and 2012. The Williams sisters did not compete as doubles partners in the 2004 Olympics when Serena had bowed out due to injury.

Serena Williams explained the stunning loss to reporters:

"It was a really tough match for us and a really tough draw, but we're used to tough draws. We honestly didn't play our best whatsoever tonight. We played terrible and that basically showed in the results."I don't know why. I wasn't playing the way I needed to play, I wasn't crossing the way I needed to cross, it was what it was. I wouldn't say it's devastating. We have a chance to compete for our country, we did the best that we can. It was a lot of fun and we will always remember these moments and these matches and at the end of the day I think that's what matters most."

Serena is reconfirmed her status as the greatest female player ever in July when she won her 7th Wimbledon women's singles title, and tying the all-time record of 22 career grand slams.

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