Di Francisca, Arianna Errigo and Vezzali won the gold, silver and bronze, producing the first medal sweep of the London Olympics.
Vezzali won gold in this event in Sydney, Athens and Beijing. A victory Saturday would have made her the first woman in Olympic history to win the same event in four consecutive Games. Only three men have done so.
Vezzali, however, fell victim to Errigo in the semifinals 15-12. The three-time champion then finished with a flourish by defeating Hyun Hee Nam of South Korea 13-12 in overtime for the bronze medal.
The gold medal match also went into overtime with Di Francisca winning 12-11.
American Lee Kiefer made it to the quarterfinals before suffering a 15-10 loss to Errigo.