NEW YORK -- Andrea Hlavackova and Lucie Hradecka, seeded fifth, knocked unseeded Serena and Venus Williams out of the U.S. Open women's doubles, 6-4, 6-2 in the semifinals Friday.
Serena Williams, who had first beaten fifth-seeded Li Na of China in a women's singles semifinal, took about an hour break and then went out onto Arthur Ashe Stadium to play doubles with her sister.
But it seemed Venus was more tired that Serena. She put many volleys into the net and struggled getting her first serve in.
Venus and Serena only play doubles at Grand Slam events and the Olympics and therefore are usually unseeded, yet they've won 13 major titles and three Olympic gold medals together. Venus, 33, has already said she'd like a chance at a fourth doubles gold in 2016 in Brazil.