After the Spartans nearly doubled up on the Portagers in the first quarter with a 13-7 advantage, things got a little tight in the second when the Portagers outpointed the Spartans, 9-7 for a four-point difference, 20-16 at the half.
Scoring was close again in the third period, but the Spartans managed to outscore the Portagers, 7-6 to make it a five-point lead, 27-22 going into the fourth quarter. The Spartans had an 11-6 advantage in the final period to separate from the Portagers.
Wren Nelson led the way for the Spartans with 12 points and was big on the boards with 16 rebounds. Adria Quigley contributed eight points and three steals.
The Spartans improved their record to 12-5, and will next be in action at home against Whitehall in the West Michigan Conference on Thursday.