Fiorentina have slipped to their third defeat of the season in Serie A, with Udinese returning to winning ways thanks to a volley from Thomas Heurtaux.
The Zebrette had Antonio Di Natale back from injury to lead the line but were put on the defensive from the outset, with Juan Cuadrado and Alberto Aquilani registering early shots on target.
Udinese lost Giampiero Pinzi to injury early on, but were still able to create the only goal of the game on 34 minutes when Heurtaux turned a cross from Di Natale into the corner with a measured volley.
La Viola dominated possession but struggled to create clear-cut opportunities in a frustrating second half, leaving Vincenzo Montella's side ruing a lack of purpose as they lost ground on the top teams in Serie A.
The scoreline could have got worse in a frantic finish, with Gabriel Silva and Luis Muriel both denied as Udinese held firm for a morale-boosting home win.
