The action was tied 1-1 at halftime but the Wildcats found three more second-half goals to seal the 4-1 victory.
Emma Peterson led the way for the Wildcats with two goals, while Allyson Balder and Kiley Miller each added a goal.
The Tigers’ Kendall Zaverl opened up the scoring in the first eight minutes with their lone goal.
Montague (7-6, 5-2) continues WMC play as it hosts the Oakridge Eagles on Thursday.
Shelby (4-12-2, 2-6-1) is set to host Fremont on Wednesday or its final home game of the regular season.