Fiorentina took the lead against the run of play, but a second half comeback gave the Zebrette all three points.
Udinese started the match much the stronger with Di Natale's freekick being headed onto the bar by Mehdi Benatia That early chance really set the tone for the entire first half with Udinese coming forward at every opportunity.
Alexis Sánchez was allowed room in the middle of the park and was causing issue for the away team, usually having to be stopped through non legal means. Di Natale was also looking lively but found himself offside more often than not, much to his own frustration.
The closest Fiorentina got to goal was through Juan Vargas but his 35 yard ballooned efforts summed up the attacking threat from the visitors. However, they did take the lead against the run of play.
Adem Ljajic played the ball inside for Santana who was given plenty of room by Armero allowing him to let fly from 35 yards out. Samir Handanovic did get a hand to the ball, but should have done better and he knew it.
Not to be disheartened by the goal, Udinese came right back at Fiorentina with Mauricio Isla and Giampiero Pinzi making some good headway down the right, but a backheel flick was the best Di Natale could muster when really he should have tried to be a little less cute.
Then just before half time the home side were up in arms as a Di Natale shot struck the arm of Alessandro Gamberini but the referee waved play on much to the annoyance of the home side who protested furiously when the half-time whistle went.
The second half started in much the same manner with Udinese going for the jugular, with Sanchez and Di Natale linking up well only for the strikers shot across goal rolling wide of the far post.
Gökhan Inler then went close with a long range effort as Udinese continued to crank up the pressure. But it was Armero who did manage to put the ball in from long range.
He smashed the ball from nearly 40 yards out leaving Vlada Avramov with no chance as the ball squeezed in between him and the post.
Continuing to pile on the pressure, it wasn't long before the home team got their second after some excellent work by German Denis. The big striker latched onto a chipped ball into the box held off Gamberini to back heel into the path of Di Natale who tucked home from six yards.
The visitors then had a magnificent chance to equalize after a freekick was floated in and no Udinese defenders followed the ball in but Khouma Babacar and Mario Bolatti couldn't get on the end of it.
The result means Udinese move up to eighth place, while the Fiorentina slide to thirteenth.
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