Baldivis will meet Rockingham in the Peel Football League grand final after a eight-point win over the Mandurah Mustangs.
The Brumbies were tested throughout the encounter as the Mustangs hit the front during the third term.
Baldivis thumped three goals on in as many minutes to douse the Mandurah flame and go onto record a 12.9.81 to 10.13.73.
Benjamin Higgs booted four goals for the victors.
The Rams and Brumbies will come together in a replay of the second semi-final.
PEEL FOOTBALL LEAGUE GRAND FINAL DAY SCHEDULE:
9:35AM - COLTS GRAND FINAL - ROCKINGHAM v BALDIVIS
12:10PM - RESERVES GRAND FINAL - ROCKINGHAM v MANDURAH
2:30PM - LEAGUE GRAND FINAL - ROCKINGHAM v BALDIVIS