Dusan Vlahovic converted a controversial early penalty and Bartlomiej Dragowski snuffed out Udinese attempts to get back into the game.
The Viola were smarting after their tense defeat to Inter, with Nico Gonzalez suspended due to that red card, and Gaetano Castrovilli injured. Udinese had lost their last two without finding the net, but Jens Stryger-Larsen returned to the starting XI.
The deadlock was broken amid controversy, because Giacomo Bonaventura seemed to go over very easily under pressure from Walace, but VAR called the referee back to look at it again and he changed his mind to award a soft penalty. Dusan Vlahovic sent Marco Silvestri the wrong way to convert.
Gerard Deulofeu wanted a penalty at the other end when he robbed Nikola Milenkovic and ran into the box, going down under Lucas Martinez-Quarta pressure, but this time the referee and VAR waved play on.
Alvaro Odriozola rolled across the six-yard box and Vlahovic couldn’t get the final touch, while Lucas Torreira blasted over from the edge of the area.
Bartlomiej Dragowski had his gloves stung by Beto and Jean-Victor Makengo after the restart, then in the final minutes there was a double chance, Dragowski at full stretch on Deulofeu’s angled drive and Beto charged down on the rebound.
Udinese 0-1 Fiorentina
Vlahovic pen 16 (F)