Friday's semifinal in Barclays Dubai Tennis Championship was the 19th professional meeting between the sisters with Venus' 6-1 2-6 7-6 (7/3) victory giving her a 10-9 advantage - the first time she has led in the head-to-head series since 2002. Venus will face Virginie Razzano.
Razzano continued her incredible week by reaching the biggest final of her career. The Frenchwoman, ranked 58th in the world, had already beaten world number two Dinara Safina and number five Vera Zvonareva, and she had little trouble brushing aside 16th seed Kaia Kanepi today.
The Estonian broke in the first game but from then on Razzano took over, winning eight games in a row before easing to a 6-1 6-2 victory.
The 25-year-old won her two WTA Tour titles in 2007, in Guangzhou and Tokyo, and last reached a final in the same year.
Razzano said: "I didn't want to give her chances. It's me who is the boss today and if she wants to beat me she has to play better than me today. I wanted to do my best today to go to the final."