MISSOULA, Mont. (AP) -- After three first-quarter turnovers the Montana Grizzlies felt the need for Sneed.
Senior quarterback Dalton Sneed came off the bench and threw for 241 yards and a touchdown to push the Montana Grizzlies past the Idaho Vandals 42-17 Saturday.
Sophomore Marcus Knight added three short touchdown runs as Montana once again rallied and improved to 8-2 overall, 5-1 in the Big Sky Conference.
Sneed, out since an ankle injury suffered at Sacramento State on Oct. 19, relieved starter Cam Humphrey in the second quarter with Idaho ahead 10-0. He led two touchdown drives in both the second and third quarters as the Grizzlies took command.
His 16-yard pass to running back Nick Ostmo on a third-and-7 signaled a momentum switch after Idaho had driven 97 yards for its first touchdown. Ostmo, a freshman, ran 7 yards for his first collegiate touchdown to cut the gap to 10-7.
Sneed's 44-yard strike to Samori Toure put Montana, ranked No. 6 in the STATS FCS poll, up 14-10 with 1:20 left in the first half. Toure had nine catches for 129 yards.
''Dalton wanted to play a week ago and we didn't feel he was ready,'' Montana coach Bobby Hauck said. ''He didn't practice on Tuesday, so I felt it was Cam's game to start. Cam had played well and we were very confident in him. But we did have a plan to play Dalton today.''
Sneed came in after Humphrey sandwiched two interceptions around a fumble by Knight - all in the first quarter.
''I felt like that was the right time and I was proud of him for coming in and doing a nice job,'' Hauck said. ''And nice job by Cam coming back and finishing it off.''
Ostmo ran for 62 yards and had two touchdowns for the Grizzlies. Knight, who had fumbled at the Idaho 5-yard line, sandwiched two short scoring runs around a touchdown pass by Idaho's Mason Petrino to Cutrell Haywood in the second half.
The latter put Montana up 35-17 with 10:09 left in the game. Idaho coach Paul Petrino, Mason's father, had hoped to build on both of the Vandals' touchdown drives.
''Those were two different situations where we should have seized the momentum and ran with it,'' Petrino said. ''And we didn't.''
Mason Petrino threw for 242 yards for the Vandals (4-6, 2-4 in the Big Sky), but lost two fumbles and was intercepted twice in the second half. He also ran for 43 yards.
Idaho standout Jeff Cotton had six catches for 98 yards but didn't play the second half because of injury.
''That Idaho team was ready to go,'' Hauck said. ''If I'm the Idaho coaches I'm pretty proud of Mason Petrino because he singlehandedly kept them in it today.''
Petrino's 12-yard strike to Connor Whitney put Idaho up 10-0 at 11:04 of the second quarter.
''Our defense held the rope for us,'' Hauck said. ''We were struggling on offense. After we got that fixed we played really well in all three phases.''
Humphrey returned to lead a fourth-quarter drive capped by Knight's third TD of the day and 17th on the season, making it 42-17 with 4:39 left.
Idaho, playing at Washington-Grizzly Stadium for the first time since 2003 - and first as a Big Sky Conference team since 1994 - committed 14 penalties and saw Tyrese Dedman ejected. Dedmon had one interception and Christian Nash the other for Idaho.
Linebacker Dante Olson had 13 tackles, a sack and a fumble recovery for Montana.
Idaho: The Vandals took advantage of some early turnovers to build a 10-0 lead but fell behind by halftime and became turnover-prone from there.
Montana: The Grizzlies got off to another slow start but rallied behind the return of quarterback Dalton Sneed, who'd missed the last two games.
Sneed: ''That wasn't me. I think anybody in here could have thrown that ball. The coaches dialed that one up, and that wasn't about the quarterback. Samori sold it great and nobody was within 15 yards of him.''
Idaho: The Vandals return home to play another Big Sky power, Sacramento State, on Saturday.
Montana: The Grizzlies stay home for a critical Big Sky showdown with No. 3 Weber State Saturday.