Zorzi carded six birdies and two bogeys to finish 11 under par, with defending champion Carlota Ciganda, South Africa's Ashleigh Simon and France's Anne-Lise Caudal sharing second.
England's Charley Hull was among a group of five players a shot further back after a flawless 66, but compatriot Holly Clyburn - joint leader after an opening 65 - could only manage a 72 to finish seven under.
"I'm happy with my game," Zorzi said. "I still tried to concentrate on each shot and didn't count my score. I was very focused like yesterday. I will try to do this and see what happens.
Zorzi's last Ladies European Tour victory came back in 2006 and she added: "There are so many good players, with 18 holes to play anything can happen.
"I don't want to put any pressure on myself. I just want to continue to play like this. Maybe someone can shoot 10 under, you never know. After such a long time, it's nice to be the leader again."
Clyburn started on the 10th and carded nine straight pars before picking up shots on the first and second, but then double-bogeyed the fourth.
"I drove it into the bunker on four and then put it into another bunker," she said. "I didn't save myself so I just took that out of my mind and played the last five holes pretty solidly.
"I birdied seven but made a bogey on nine because I went a bit long and then a bit too aggressive with my chip shot, but other than that I was pretty happy with the performance.
"Probably, because I'm trailing I will be more aggressive tomorrow. After my performance today I do feel more confident off the tee. I've got nothing to hold back for tomorrow. I can go all guns blazing tomorrow and the leaders can protect their score so I'm quite happy with where I am."