Alessio Cerci scored the only goal of the game 10 minutes before the break, slotting home from the left side of the box after latching onto Ruben Olivera’s through ball.
Andrea Esposito came within a lick of paint of equalising early in the second period but he headed Andrea Bertolacci’s corner against the bar.
“I haven’t taken Fiorentina to safety. This is a job done by two coaches, in particular by Rossi over the last few weeks,” the trainer Guerini said.
“We’ve avoided the humiliation of having to play for safety on the last day of the season. I have to compliment the lads, they played in terrible physical conditions. Loads of them couldn’t play, and other who hadn’t played in a long time did really well.”