The Cougars outscored the Panthers 16-0 in the third quarter during a monster run that gave HF-L the lead.
Geneva led 15-1 after the first quarter and did not allow a Cougar field goal until nearly ten minutes were gone in the contest.
Riley Morien led HF-L with 14 points.
Geneva did most of their damage with the bigs. Alisia Griffin had 16 points to lead all scorers while Mia Morrison added 13.
HF-L will face top seeded Mendon in Thursday's championship game at Gates-Chili High School. The Vikings narrowly avoided their own upset, nipping (4)Sutherland 46-45 on a three pointer with 22 seconds to play.