World No. 1 Serena Williams needed less than an hour to defeat her sister, Venus, by 6-1, 6-2 in the Family Circle Cup semifinals today on Daniel Island.

The sisters, with 22 Grand Slam tennis titles between them, met for the 24th time as pros. Serena, 31, has won five straight and owns a 14-10 lead over the 32-year-old Venus, currently ranked No. 24.

It was the biggest margin of victory in matches between the two. Serena took a 6-2, 6-2 win in the semifinals at Miami in 2002.

A crowd of 9,412 fans turned out for the siblings’ semifinal, the largest single-session attendance since the tournament moved to Charleston in 2001.

Serena, seeking her third Family Circle Cup title and second straight, will play in Sunday’s 1 p.m. final against the Jelena Jankovic-Stefanie Voegele winner.