Pittin arrived in Italy in electric form having won the last three World Cup rounds but it was all about overall leader Lamy-Chappuis who dominated the home-crowd favourite.
Victory leaves the 2010 Winter Olympic gold-medallist Lamy-Chappuis on 856 points in the World Cup rankings with closest rival Pittin, 21, facing an uphill battle to claw back a 182 point deficit.
The Italian could only manage tenth on home soil in the 10km penalty race – nearly 40 seconds adrift of his arch-rival.
Lamy-Chappuis’ comfortable victory came in a time of 26:58.6 minutes, five seconds ahead of Germany’s Bjoern Kircheisen with Norway’s Mikko Kokslien taking third.
Another German, Eric Frenzel was fourth, clocking 27.04.9 minutes followed by Japan’s Akito Watabe.