BOISE, Idaho — Ashton Jeanty ran for 209 yards and a touchdown and No. 10 Boise State earned a College Football Playoff spot, beating No. 19 UNLV 21-7 on Friday night for its second straight Mountain West title.

Boise State (12-1, No. 10 CFP) is all but assured of a first-round bye in the playoffs if it maintains its ranking ahead of the Big 12 winner and finishes as one of the four highest-ranked conference champs.

“In January when they were playing tug of war on the field with their shirts off, they talked about what they wanted to do this season,” Boise State coach Spencer Danielson said. “They wanted to win a conference championship and make it to the college playoffs, and they worked for that.”

Jeanty, who had the spotlight to himself to state his Heisman case, didn’t disappoint, ripping off an electrifying 75-yard touchdown run. It was his fifth TD run of 70 yards or more this season, tying LaDainian Tomlinson’s FBS season record.

Jeanty also surpassed 1981 Heisman winner Marcus Allen of Southern California to move into fourth place on the FBS season rushing list (2,497 yards) and needs 132 more to pass record-holder Barry Sanders of Oklahoma State. On Friday, he amassed 209 yards on 32 carries.

Maddux Madsen threw a touchdown pass and rushed for another score for the Broncos.

UNLV (10-3, No. 20 CFP), which entered the game seventh nationally in scoring offense averaging 38.7 points, hadn’t been held below 23 this season.

“I have been in championship games before and come up on the wrong end of them,” UNLV coach Barry Odom said. “But you continue to learn from them and move your organization forward and find a way to get back to a game like this and win it.”

However, Odom didn’t mince words when describing how he felt about Boise State, which handed his team two of their three losses.

“Good luck to anyone who comes here and thinks they’re going to win the game,” Odom said. “I think they’re one of the best teams in college football right now. And I think they’ll do a great job representing this conference. They’re built to make a run.”

With UNLV loading the box with eight or nine defenders early in the game, Boise State leaned heavily on Madsen in the first quarter. And he delivered, completing six of his first seven passes, including a 22-yard scoring strike to Latrell Caples for a 7-0 lead.

Madsen used his legs to put the Broncos ahead 14-0, scrambling for a 14-yard TD run with 2:40 left in the first half.

After a quick stop, Boise State got the ball back and let Jeanty work his magic. Two plays later, he raced through the teeth of the defense and sprinted to the end zone for a 75-yard TD run, giving the Broncos a 21-0 lead with 29 seconds left in the half.

UNLV had a chance to claw back into it late in the third quarter when Kylin James raced 86 yards before Seyi Oladipo ran him down at the Boise State 5. But the Rebels lost 4 yards on the next four plays and failed to score.

The Rebels finally got into the end zone with 9:06 left on a Greg Burrell 31-yard run.

Hajj-Malik Williams led UNLV offensively with 110 yards passing and 56 yards rushing.