Azarenka is seeking a tour-high fifth tournament title of the year.
She dominated the match against the fourth-ranked Radwanska, whose four losses of the year have come against Azarenka.
On match point, Azarenka fired a forehand winner to advance to the final. She is 29-1 for the year.
Sharapova is off to a promising start to her clay-court season. The Russian broke serve in the fifth game and did not face a break point of her own in the first set.
That changed in the second.
Kvitova held 11 break points in the set, but the Czech could not convert any.
She did convert her 12th -- after saving a match point -- to even the score at 6-6 and sent the second set into the tiebreaker. Sharapova made fewer mistakes and now seeks her first title of the year.
Azarenka leads Sharapova 5-3 in career meetings.