With both sides having a victory against each other, the scene was set for a hotly contested match at Tarrawingee Recreational Reserve.
From the start of the game, the Bats hit the ground running to be within a point of the Demons at the end of the first quarter.
Once the second term started, the game was as good as done as the Bats kicked seven goals to none to head into the change rooms with a 43-point lead.
A new half, a similar result as the Bats extended the lead to 53 by three-quarter-time.
A five-goal-to-three last quarter secured Bats a qualifying final match-up with Bright, who had a 40-point win over King Valley.
Best on a brilliant day for the Bats were Alex Moloney, who intercepted everything that came his way, along with Charles Hunter and Rhys Goodley, who kicked four goals each.
Goorambat 2-6 8-11 14-13 19-15 129
Milawa 3-1 3-4 6-7 9-11 65
Best players: Alex Moloney, Charles Hunter, Victor Butler, Curtis Anker, Jamie Dunne, Sully Malay.
Goals: Charles Hunter 4 , Rhys Goodley 4, Brush Haebich 3, Braydon Wapling 2, Darcey Edgar, Angus Buston, Kobe Black,Victor Butler, Brayden Stepien and Sully Malay.