In Saturday's semi-finals, eighth-seeded Peng defeated Romina Oprandi of Switzerland in a tough three-setter 6-4, 2-6, 6-4.
Kanepi moved into the final by edging Jamie Hampton of the United States, 7-6 (8/6), 6-4.
The players were given a few hours rest before their final later on Saturday.
Peng, ranked 34th in the world, reached the final in 2011.
Kanepi is 40th in the WTA rankings and reached the semi-finals in Brussels last year.
All week, the tournament has been affected by rain, hail, cold and wind, forcing the semis and final to be played on the same day, this time under sunny skies.