Air Force Academy, Colo. — Jeremy McNichols, one of the nation’s leading rushers, was stuffed, stymied and stood up on three cracks from inside the 5. A quarterback sneak didn’t work, either.

Wyoming certainly appreciated it.

The Falcons had a late goal-line stand, Tyler Weaver returned a blocked punt 11 yards for a first-half touchdown and Air Force beat No. 20 Boise State, 27-20, on Friday, ending the Broncos’ bid for the Mountain West title.

Wyoming will face San Diego State in the conference championship game Dec. 3.

With the loss, Boise State also eliminated itself from contention to be the Group of Five representative in the Cotton Bowl. In this week's College Football Playoff rankings, Boise State was No. 19 and Western Michigan was No. 21. Western Michigan is now the favorite and has one game remaining, the MAC championship against Ohio University.

Haji Dunn Jr. recovered quarterback Brett Rypien’s fumble on fourth-and-goal from the 1 with just under 2 minutes remaining to help the Falcons (9-3, 5-3 Mountain West) knock off Boise State for a third straight season. They join Idaho (1982-93) and Nevada (1996-98) as the only teams to beat the Broncos in at least three straight years.

“Thank goodness they didn’t run wide,” said senior safety Brodie Hicks, who forced the fumble. “We put all our marbles inside.”

The Broncos (10-2, 6-2, No. 19 CFP) needed a win at Air Force and for New Mexico to upset Mountain Division-leading Wyoming on Saturday to earn a spot in the conference’s title game.

No reason to watch now.

“It’s like an empty feeling,” Boise State receiver Cedrick Wilson said. “We wish we could have pulled through like we practiced but sometimes you fall short.”

Boise State’s loss cracks open the door further for undefeated and No. 14 Western Michigan to get into the Cotton Bowl following its 55-35 victory over Toledo.

McNichols rushed for 60 yards — and a score — on his opening two carries, but was held to 28 yards the rest of the way. He had three carries at the goal line on Boise State’s last possession, but couldn’t get in.

On fourth down, Rypien tried to sneak it in only to have the ball knocked free by Hicks. Dunn was there to recover it.

“It’s a game I thought we prepared well for and our guys were looking forward to coming in here and playing our best football,” Boise State coach Bryan Harsin said. “We didn’t do that tonight, so a lot of disappointment in the locker room.”

Off target most of the day, Rypien found his touch in the fourth quarter and led a spirited Broncos rally. He hit Wilson for a 75-yard TD pass to pull Boise State to 27-20 with 8:50 remaining. He wound up a yard shy of possibly tying the game.

Brett Baldwin gave the Falcons a big boost when he broke through and blocked a punt by Sean Wale just before halftime. Weaver caught the ball out of the air and ran it in to give Air Force a 17-7 lead.

Air Force took advantage of a Boise State defense that was missing several starters by running it up the middle. Falcon fullbacks D.J. Johnson and Shayne Davern combined for 25 carries and 111 yards up the middle. Johnson scored on a 1-yard plunge in the first quarter and Davern on an 8-yard run in the third.

“You don’t know how much it meant to go out and win this way,” Hicks said. “We as seniors had to leave behind something to be remembered for.”