The Spartans took a 7-0 lead in the opening quarter before Fremont answered with a 25-yard rushing score from Wei Ping Chen.
Fremont’s other scores came on a 40-yard pass from Kaleb Koomen to Nathan Hoffman and a second TD run from Chen of 78 yards.
Chen finished with 192 yards rushing on 26 carries and Koomen was 7-of-17 passing for 186 yards.
Hoffman had three catches for 120 yards for the Packers.
William Gates led the Fremont defense with 14 tackles and Logan Stanley added 12.