Michael Matthews won his first Giro sprint win and consolidated his position atop the overall standings. The Australian had finished seventh on Day 2, which enabled him to get a 10-second bonus for winning on Monday.
Italy's Fabio Felline finished second ahead of Belgian Philippe Gilbert.
"What more can you ask for?" Matthews said after the race. "I'm racing with the pink jersey on my back and at the end I win the stage.
"After the Team Time Trial win, today was another big target for us. We reconned the stage last week so we knew what to expect, and we pulled it off."
The race also saw a tragic crash of Domenico Pozzovivo. The Italian fell face first on a fast downhill section located about 38 km from the finish. Race doctor Giovanni Tredici quickly dismissed fears amongst spectators by noting that he was out of danger.
"I was really afraid," said Pozzovivo's teammate Hubert Dupont, who was first to the scene. His eyes were rolling and it seemed such a long time before medical assistance arrived."
Pozzovivo was taken to San Martino hospital in Genoa. "The tests carried out at the hospital show that he is in a stable condition," said Tredici.