Sharapova dominated the opening exchanges and eventually claimed the opening set 6-3 after 40 minutes of hard-hitting action.
The last six meetings between the pair had been decided in straight sets, but Azarenka ensured that this encounter would go the distance by winning the second 6-2.
She had reduced her error count dramatically since the opening set and she was now matching Sharapova in the winners department.
As the court thermometer peaked at 32C° during the set interval, the players were allowed to take a 10-minute break.
Azarenka seemed to be the keener of the two to resume play and it was she who made the brighter start in the deciding set.
The Belarusian held her first five service games with relative ease, while Sharapova was taken to deuce in all of hers.
Serving to stay in the match at 4-5, the pressure finally took its toll on the Russian.
Azarenka dominated the final game and converted her second match point when Sharapova's lofted forehand floated long.