Bammer broke Schiavone twice for a 4-0 lead in the first set on Sunday before the Italian rallied to tie the score at 5-5.
Schiavone then took a 3-1 lead in the tiebreaker before Bammer seized control.
The 31st-ranked Bammer then broke Schiavone twice for a quick 5-1 lead in the second before sealing the win.
The rain-delayed semifinals were played earlier Sunday. Bammer beat Iveta Benesova of the Czech Republic 6-0, 7-5, while Schiavone struggled for 2 hours, 30 minutes before overcoming unseeded Timea Bacsinszky of Switzerland 6-2, 4-6, 7-5.