The Lampre rider claimed his second stage win of this year's edition after being perfectly set up by his team mates.
He beat compatriot Giacomo Nizzolo (Trek) and Slovenian Luka Mezgec (Giant-Alpecin), who were second and third respectively.
Spain's Alberto Contador retained his overall leader's pink jersey after finishing safe in the bunch.
The Tinkoff-Saxo rider leads Astana duo Mikel Landa, of Spain, and Italian Fabio Aru by four minutes two seconds and 4min 52sec respectively.
Original source: Modolo wins Giro d'Italia stage 17