Fiorentina dominated from start to finish with Adem Ljajic and Stevan Jovetic both scoring twice for the Viola.
Milan: Inter Milan had a worse night and their poor run continued with a 4-1 humiliation at Fiorentina, with Adem Ljajic and Stevan Jovetic both scoring twice for the Viola.
Fiorentina dominated from start to finish and took the lead when Jovetic nodded on Manuel Pasqual cross for Ljajic to head home in the 13th minute.
Jovetic doubled his side's advantage 20 minutes later, curling a stunning strike into the top right corner, and he scored his second of the game following more poor defending by Inter after the break. Inter failed to clear the ball and a delightful backheeled flick from Alberto Aquilani sent Jovetic clean through.
Ljajic grabbed his second of the night in the 65th. Borja Valero slotted the ball across to him and he curled into the top right corner. Antonio Cassano grabbed a consolation for Inter with an unstoppable 30-yard rocket into the bottom left corner. It was Inter's only shot on target all match.
Edinson Cavani went agonizingly close at the end when he poked an effort just wide from close range. Inter Milan is eight points behind Napoli after its first loss to Fiorentina since 2006. Andrea Stramaccioni's team has now only won twice in its past nine league matches and faces in-form city rival AC Milan next weekend.
"I saw my Inter team in real difficulty tonight, very tired," Stramaccioni said. "Tonight Inter was really ugly. But I believe that this season such defeats can have little effect. I remember AC Milan lost 4-2 to Roma and then bounced back.
"But we paid for our tiredness from the Europe League more than I could have imagined. Maybe I made mistakes in my choices."