Goals in each half from Steven Jovetic and Luca Toni handed Fiorentina all three points against Catania at the Stadio Artemi Franchi.
Montenegro forward Jovetic put the hosts ahead just before half-time and veteran striker Toni sealed victory moments after stepping off the bench.
The victory was Fiorentina's second in three matches, with Catania suffering their first defeat of the new campaign.
Giulio Migliaccio failed to work Mariano Andujar with the first opening of the match, his shot heading tamely towards the visiting keeper.
Andujat had another simple save to make after 15 minutes when Jovetic tried his luck, while Borja Valero missed the target with a shot from range.
A goal looked unlikely to come before the break until, in the 43rd minute, Jovetic got on the end of Manuel Pasqual's pass and steered his shot home.
Catania had been completely lacking in attack in the first half and at least tried to bring themselves into the game just after the restart, although Gonzalo Bergessio's weak attempt did not detain Emiliano Viviano long in the Fiorentina goal.
Indeed, it took until the 65th minute for a second goal to arrive with Toni, having just replaced Adem Ljajic, handed the simplest of tap-ins following great approach work from Jovetic.
Again Catania struggled to form a serious response. Bergessio was the most willing outlet up front but in the 69th minute again fluffed his lines to hand Viviano a straightforward save.
Souleymane Doukara had the final attempt for Catania in the closing seconds but lifted his effort over the crossbar.