Torro-Flor defeated fifth-seeded compatriot Garbine Muguruza 6-0, 6-3.
It's the first WTA final for both unseeded players.
Oprandi, playing the full main tour since 2005, is just four tournaments into her comeback following nine months out with a right shoulder injury, which she sustained last year during a breakthrough season.
Torro-Flor missed the Australian Open because of a left leg injury and won only three matches this year entering this week. But she's knocked off two seeds and hasn't dropped a set to make the final on Sunday.
She beat Oprandi in their only previous meeting, two years ago in Bucharest.
- Sports & Recreation
- Romina Oprandi
- Daniela Hantuchova