Williams sisters in Doha final

DOHA, Qatar, Oct. 31 (UPI) -- Sisters Serena and Venus Williams meet Sunday in the season-ending Sony Ericsson women's tennis Championships in Doha, Qatar.

The matchup was determined Saturday both sisters won semifinal matches. Serena Williams went through round-robin play undefeated to get to the semifinals but Venus Williams, 1-2 in the round-robin matches, needed help and it came Friday when third-seeded Svetlana Kuznetsova beat fellow Russian Elena Dementieva, the fifth-seed, 6-3, 6-2.

Kuznetsova and Dementieva also went 1-2 in Maroon Group matches, but Venus Williams, the seventh seed and defending champion, advanced by winning more sets in the first four days.

Serena, the second seed, beat Denmark's Caroline Wozniacki, the fourth-seed, 6-4 1-0 when Wozniacki retired because of a left abdominal strain.

Wozniacki also was hampered by a leg injury throughout the week.

"It's so good to see a face like hers on the tour," Serena said. "She's an incredible fighter."

If Serena (4-0) wins Sunday's final, she would make $1.55 million for being unbeaten the entire event.