Antonio Cincotta s side made a fine start to the contest, caging the Bianconere in the opening stages until Arianna Caruso set up Barbara Bonansea for Juve s opener five minutes from the half-time break.
Some 10 minutes after the restart, Bonansea doubled the lead for Juventus when she netted from the right corner, for her brace of the day.
Fiorentina, however, fought to come back into the tie thanks to attempts from Kim, Tatiana Bonetti and Valery Vigilucci but they could not beat in-form goalkeeper Laura Giuliani.
The result saw Kim and Fiorentina miss the chance to celebrate their first silverware this season at the expense of Juventus.