Azarenka gained the championship match with a 6-0, 4-6, 6-3 defeat of seventh-seeded Ana Ivanovic of Serbia in the day's first semifinal match.
The Belarusian will be looking for her third crown of the year against fifth-seeded Australian Stosur, who advanced with a 7-6 (7-2), 6-3 victory over French wild card Virginie Razzano.
Stosur will need to overcome an 0-8 lifetime record against Azarenka if she is to win her fourth career title in Sunday's final.
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