Reynolds had 20 carries for 112 yards and three touchdowns and Brooks-Fletcher ran for 133 yards and a TD on 22 carries for the Grizzlies (7-0, 4-0 Big Sky), who own a 15-0 overall record against the Hornets.
Trailing by a touchdown, Reynolds tied the game 14-14 on a 2-yard TD run with 6:34 remaining in the second quarter.
After quarterback Gerald Kemp recovered an on-side kick for Montana on the kickoff, Reynolds scored on a 1-yard run to give the Grizzlies a 21-14 halftime lead.
Reynolds had 17 carries for 100 yards and wide receiver Marc Mariana caught an 18-yard touchdown pass in the first half for the Grizzlies.
Reynolds scored his third touchdown on a 5-yard run in the third quarter while Brooks-Fletcher's lone TD came on a 17-yard run to make the score 35-21 just before the half.