Late goals from Ziegler and Cassano give the home side victory after Marchionni headed in early for La Viola.
Sampdoria were very slow in the opening stages of the game with Fiorentina showing greater energy with Adem Ljajic in particular impressing with his ability to find space between the Samp midfield and defence.
It wasn't long before La Viola took the lead as Marco Marchionni met a Juan Vargas cross with a bullet header to give Fiorentina a much deserved lead. Though the Sampdoria defence will be asking how the midfielder was able to get a free header in at the back post.
Fiorentina were piling on the pressure as Samp could barely string any passes together with Angelo Palombo a noteworthy culprit and the sustained pressure nearly produced a carbon copy of the goal but this time Marchionni's header went just wide.
It wasnlt until the 20 minute until the home team started to get any footing in the match with long range shots from Fernando Tissone and Reto Ziegler going just wide.
Then soon after Sebastian Frey produced a wondersave from a Giampaolo Pazzini header, and the keeper then produced another excellent stop as he dove to the ground to deny Antonio Cassano.
As the half drew to a close Samp grew more and more frustrated with a number of rash challenges going in.
The second period started with Sampdoria on the front foot but they could not make the territorial advantage count. Pazzini had a decent penalty claim denied as he looked to have been brought down by Cesare Natali.
The frontman then had another strike at goal which he sliced wide. By this point Fiorentina were looking desperate and trying everything they could to slow the game down.
But the away team couldn't hold out for the rest of the game as Ziegler fired an unstoppable free-kick past Frey from 35 yards to bring his side level then Cassano put his team ahead in sensational fashion as he drifted past one man, then another and cut back on himself before wrong-footing Frey by rolling the ball into the back of the net.
The stunning victory takes Sampdoria up to seventh in Serie A, while Fiorentina are now rooted to the foot of the table and Sinisa Mihijlovic will surely be out of a job sooner rather than later.
Keep up to date with Serie A and Italy news with Goal.com's Italy page and join Goal.com USA's Facebook fan page!