The Azzurri briefly threatened to derail France's attempt at a first title since 2010 when debutant teenager Tommaso Menoncello scored.
But Anthony Jelonch and Gabin Villiere crossed to put the hosts in front.
After the break, Villiere completed his hat-trick and Damian Penaud also crossed to secure the bonus point.
France top the table after round one from second-placed Ireland on points difference, with Andy Farrell's side travelling to Paris in round two.
Rain fell on the Stade de France for most of the match, but France were still able to display the many options in their box of attacking tricks.
From the outset, the hosts showed off a backline of devastating runners and a sharp kicking game to the jubilant Paris crowd.
But Italy clearly had not read the script and started strongly too, taking an unexpected lead when Paolo Garbisi's cross-field kick set up 19-year-old wing Menoncello to become the youngest try scorer in the tournament since 1967.
France soon hit back as Italy scrum-half Stephen Varney tried to recover from a messy line-out but popped the ball into the hands of the onrushing Jelonch, who scored an interception try.
Italy briefly went ahead again after a Garbisi penalty, before Jaminet claimed three points too, and France asserted their dominance before the break as speedy offloads created space for Villiere to slide across in the left corner.
A Julien Marchand try was ruled out, but France could not be kept out for long as Villiere hung on the shoulder of Gregory Alldritt to grab the ball and step round two Italian defenders to score.
Italy managed to keep France quiet for another 20 minutes before the hosts' quality was too much for the Azzurri as Penaud combined with World Player of the Year Antoine Dupont to secure the bonus-point try.
Again French pressure built and, with the clock in the red, Villiere completed his hat-trick in a solid start to the tournament for Les Bleus.
For Italy, despite having now lost 33 Six Nations games in a row, there were signs of promise which they will hope to build on when they host England in round two.