Starting from the 10th hole at Adriatic Golf Club Cervia in an early morning start, Pavan delivered a flawless round to set the clubhouse target which was later matched only by Denmark's Sebastian Friedrichsen and American Gunner Wiebe.
Sweden's Marcus Kinhult, who lost in a play-off for the Dutch Open on Sunday, was a shot off the lead alongside Malaysia's Gavin Green, while former Masters champions Patrick Reed and Danny Willett shot 69 and 72 respectively.
Pavan had missed the cut in seven of his first 10 events of the season but finished fourth in Amsterdam last week, just a shot outside the three-man play-off won by compatriot Guido Migliozzi.
"In this game it's tough but you just try your best and sometimes you know you're playing well and it can carry on," Pavan, a two-time winner on the European Tour, said.
"I had not played here in a long time so I didn't feel like I really knew the golf course but today was good. I played very well. I was in position and hit it close. The course is not very long but you still have to play well.
"I think it has very small greens, especially on the back nine, so if you hit the green you're quite close most of the time.
"It has a little bit of rough around the greens and a few trees off the tee but overall it's a type of golf course that if you play well it feels like you can shoot a low score, but if you're a little off it can still bite a little bit."
England's Joe Dean, who contested the Dutch Open play-off with Migliozzi and Kinhult, continued his good form with an opening 68, while Migliozzi returned a level-par 71.
The Australian duo of Haydn Barron and David Micheluzzi had solid starts with one-under par rounds of 70 that left them in a log-jam of players in joint-51st place.
7°C