The Tigers are now 12-6 overall and 11-5 in the FCIAC.
Ridgefield led by just five points, 11-6, after the first quarter but then outscored the Senators, 47-26, over the next two quarters to open a 58-32 lead going into the final period.
Sandy Carpenter hit four three-pointers and led the Tigers with 22 points. Andrea Ferrero also reached double figures, finishing with 13 points.
Carly Mercede (nine points), Rebecca Lawrence (eight), Samarah Cook (seven), Kaitlyn Birch (three), Maggie Scalzo (two), Paige Andrews (two), Emma Glubiak (two), and Maddie Wiley (one) also scored for Ridgefield.
Three players had seven points apiece for McMahon, which dropped to 2-16 overall.