BEIJING — Venus and Serena Williams have clinched at least a silver medal in doubles with a victory in the Olympic semifinals.

The sisters beat another sibling pair, Ukraine's Alona and Kateryna Bondarenko, 4-6, 6-4, 6-1, on Saturday.

The Williams sisters improved to 9-0 lifetime in Olympic doubles. They won the gold medal at Sydney in 2000 but didn't play doubles in 2004 because Serena was hurt.

Both were beaten in the quarterfinals of singles Thursday.

Seeded second, the sisters will play Sunday against the winner of the semifinal between Yan Zi and Zheng Jie of China and Anabel Medina Garrigues and Virginia Ruano Pascual of Spain.