Vinci gave Italy a 3-1 lead in the best-of-five playoff against the defending champion. The match was played before a sparse crowd, with most visiting fans having traveled home Sunday.
Italy will play for the championship in November against Russia, which defeated the Slovak Republic in Sunday's other semifinal.
Vinci recovered from a 5-3 deficit in the second set to serve for the match at 6-5. Safarova broke back to force the tiebreaker, which she dominated. Vinci then broke for a 5-3 lead in the third set before winning on her third match point.
The final doubles match was canceled.