The 30-year-old Vezzali beat her friend and rival Giovanna Trillini in the women's all-Italian final.
"This morning I cried because of the stress. But then I felt free and without stress. I didn't think of the gold at all, I just followed my trainer," said Vezalli.
As she left the arena, Vezzali received a congratulatory telephone call from Italian President Carlo Azeglio Ciampi.
"I told him that he brings luck to the team because he was at the hall when Aldo Montano won the men's sabre and I said that next time we meet I will give him my gold medal," she said.
Asked about her future, Vezzali said: "I want to have a baby."
Trillini scored the only hit of the first three-minute round as Vezzali struggled to impose herself.
But with the scores level at 6-6 at the start of the third and final round, Vezzali won three successive points to build a cushion that she never relinquished.
Trillini said the two women, who both come from the small town of Jesi in eastern Italy, had not talked all day.
"We just kept out of each other's way," she said.
The 34-year-old Trillini, who has now won seven Olympic medals, suggested she would take a year off before making a decision about her future.
The 22-year-old Sylwia Gruchala of Poland won the bronze after a 15-9 win over Hungarian Aida Mohamed.