The Fiorentina Supporters Association (ATF) boycotted the opening 45 minutes of Sunday's goalless home draw with Bologna in protest against the club's ownership.
Brothers Andrea and Diego Della Valle, who are billionaires through their luxury shoe company Tod's, bought the club in 2002 after it had been declared bankrupt and relegated to Italy's fourth tier. However, ATF has accused the owners of failing to invest since then and made its feelings known.
Fans spent the first half inside the stadium...
Atalanta blasted four goals in the opening 15 minutes against Bologna to move within a point of the top four after a 4-1 win in Serie A on Thursday.
The result edged Atalanta closer to the Champions League qualifying places with eight games remaining, while Bologna dropped back into the relegation zone only four days after climbing out of it.
Josip Ilicic put Atalanta ahead with a delightful curling effort in the third minute and the Slovenian added a second from a tight angle two minutes later.