The Grizzlies (5-5, 3-4 Big Sky) led 10-7 at halftime, but Weber State took the lead on Kris Parham's 1-yard run in the third quarter before Montana rallied.
The Wildcats (1-8, 1-5) closed in after Chris Lider's third field goal, a 35-yarder, made it 24-14 Montana. Cordero Dixon returned the kickoff 100 yards for a score with 3:41 to play, but Weber State never got the ball back.
Peter Nguyen ran for 103 yards for Montana, which won consecutive games for the first time this season. The Grizzlies have one game remaining, at home against Montana State in two weeks. Weber State's only win of the season came in its previous game, two weeks ago at Southern Utah.
Ohio State remained No. 1 in the AP Top 25 and tied a poll record Sunday despite lagging support from voters. Meanwhile, No. 2 TCU and No. 3 Baylor edged forward and No. 4 Michigan State slipped.
Texas cornerback Kris Boyd has apologized for retweeting a Texas A&M fan during halftime of Texas' 50-7 loss to TCU on Saturday.
The Big 12 on Sunday acknowledged an officiating mistake that incorrectly awarded Oklahoma State a first down Saturday and said the officials involved would be disciplined.
Georgia coach Mark Richt says he's sticking with Greyson Lambert, who was just 10-for-24 for 86 yards in a loss to Alabama, as the Bulldogs starting quarterback.
Will Grier threw four touchdown passes to four receivers -- all in the first half -- and No. 25 Florida downed third-ranked Mississippi 38-10 on Saturday night.
Leonard Fournette highlighted his SEC-record third straight 200-yard game with a 75-yard touchdown run, and No. 9 LSU overcame Eastern Michigan 44-22 on Saturday night.