The scoring began when Hart tallied goals from Osiel Deblas and Kenneth Diaz in the first half.
Just before halftime, the Wildcats responded with a goal from Daniel Lipka to go into half trailing 2-1.
In the early part of the second half Montague tied the game when Sam Siemer found the back of the net.
Both teams went scoreless for the rest of the half and through the first overtime.
Hart got the winning goal in the second overtime period when Austin VanderLaan scored off an assist from Dylan Vanderzwaag.
Hart had an advantage in shots on goal over Montague, 15-3.