Safina had lost all her previous matches against Nadia Petrova
Dinara Safina and Svetlana Kuznetsova both claimed comfortable straight-set wins to set up an all-Russian final at the Pan Pacific Open in Ariake, Japan.
Safina, the world number five, crushed Nadia Petrova 6-1 6-0 - her first win over her compatriot in six attempts.
And Kuznetsova, ranked seventh, brushed aside Katarina Srebotnik 7-6 (7-5) 6-2.
Kuznetsova started slowly before taking the first set against the Slovenian qualifier but, at 2-2 in the second, she won four straight games to triumph.
Safina is looking forward to facing Kuznetsova in the final.
"It's great. We are good friends, so I just hope that we can go out there and play a good match," she said.
"Let's see who is going to be stronger on the day and win."