The eighth-seeded Monfils will play for the title Sunday against 2004 champion Feliciano Lopez or Philipp Petzschner.
Monfils is 1-4 in career finals and could become the fifth Frenchman to win an ATP event this year after Gilles Simon, Michael Llodra, Fabrice Santoro and Jo-Wilfried Tsonga.
Monfils, the only seeded player in the semifinals, broke Kohlschreiber at 3-3 and saved four break points against his serve to take the opening set. The second went with serve until 6-5 when Kohlschreiber used the only chance to crack Monfils' serve and even the match.
In the deciding set's third game - the longest of the match - Kohlschreiber fought off six break points but lost the game when Monfils hit a backhand passing shot on his seventh chance. Monfils missed three match points when he led 6-5 and 40-0, but used a fifth chance to close the match in the tiebreaker.
Monfils upsets Gonzalez in Vienna
Casillas Wary Of Wounded Atlético
Monfils upsets 2nd-seeded Gonzalez
Mijatovic: Keep Up The Rotation, Bernd
