The 24-year-old was first out of the start hut with bib number one on a crisp and sunny morning and stayed top as others failed to come close to his benchmark time of one minute 45.19 seconds.
Austria's Stefan Babinsky was second, 0.35 slower after starting fourth, with home Swiss hope Franjo von Allmen third and 0.37 off the pace.
Switzerland's Marco Odermatt, the overall World Cup and super-G leader as well as a big medal favourite for next month's Milano Cortina Olympics, could manage only fourth from 12th on the starting list.
The podium was Franzoni's career second, after finishing third in a Val Gardena super-G in December, and with the Olympics looming indicated the Italian was coming good at just the right time.
Teammates Dominik Paris, Guglielmo Bosca and Marco Abbruzzese all failed to finish Friday's race, the fifth super-G of the season.
The Italian women's team have had one win so far this season with Sofia Goggia, also in super-G.
Austrian Marco Schwarz, winner of the previous super-G on Italian snow in Livigno, did not start the race after suffering from flu and returning home.
Odermatt remained comfortably ahead in the super-G standings with 325 points, 94 clear of Austrian Vincent Kriechmayr who was 12th on Friday. Franzoni is third overall, 107 off the lead.
