Sharapova lost to Azarenka in the finals of the Australian Open and Indian Wells this year, and had never beaten her rival in four previous encounters in a final.
The Russian won her 25th career title, an honor roll that also includes three Grand Slam championships.
Sharapova made her debut this year in Stuttgart, a tournament played on indoor clay.
Sharapova won her fifth clay court title while Azarenka lost her second match of the year.
- Maria Sharapova
- Victoria Azarenka