Doha, Qatar -- (Sports Network) - Serena Williams and her sister Venus will meet again in a championship final, as both advanced in very different ways during Saturday's semifinals at the $4.55 million Sony Ericsson Championships.

Venus inched her way through round-robin action and into the final four despite a 1-2 mark, then advanced to her second straight final in this event with a 5-7, 6-3, 6-4 victory over Jelena Jankovic.

Serena, who captured the group with a perfect 3-0 record, moved into Sunday's final when Caroline Wozniacki retired with a left abdominal strain while trailing 6-4, 0-1.

In the final, Serena will not only face her sister, but another opponent fighting injury. Venus needed treatment on her knee multiple times during the match, yet still persevered in a grueling three-set bout.

Venus is the first player since Amelie Mauresmo in 2003 to reach the final of this event with two losses at the Khalifa Tennis Complex.

It wasn't easy. Jankovic broke Venus at 5-5 in the first set, then held her serve to win the first set. She coughed up a lead in the second set and lost her serve three straight times in the final deciding set.

Serena played for just 45 minutes in her match and now gets another match against her sister, whom she beat 5-7, 6-4, 7-6 (7-4) earlier in round-robin play. Serena leads the all-Williams series with Venus, 12-10, including three straight victories.

No matter what happens in Sunday's final, the Wimbledon and Aussie Open champion Serena will close out 2009 as the No. 1 women's player in the world.