The ninth-ranked Cougars survived their lowest-scoring game of the season, beating New Mexico 21-3 on Saturday to extend the nation's longest winning streak to 16 straight.
BYU (6-0, 2-0 Mountain West) remained unbeaten at the halfway point of the season, but needed Max Hall's 8-yard touchdown pass to Austin Collie with 3:05 left in the game to seal it.
New Mexico had just had a touchdown called back on a penalty and then failed to convert on fourth-and-21. The Cougars weren't expecting any more breaks.
"I said we have to score. If we're going to put this game away we have to score on this drive," said Hall, who threw for all three of BYU's touchdowns.
New Mexico (3-4, 1-2) held BYU scoreless in opening quarter and scored before BYU, two things that hadn't happened to the Cougars this year. BYU, which had outscored its first three opponents at home 144-17, led only 7-3 at halftime and just 14-3 entering the fourth quarter.
"They had a good strategy to keep us off the field. We didn't have as many chances as we'd like," said Harvey Unga, who ran for 95 yards on 22 carries. "We're definitely not used to that kind of halftime score. But we were up and we couldn't let that go out of focus."
Collie had nine catches for 170 yards, his fourth straight 100-yard receiving game, and Hall finished 22-of-34 for 273 yards.
The Cougars had scored at least four touchdowns in every game until Saturday. They still managed to win their 16th straight at home and remain unbeaten for Thursday's game at TCU.
Rodney Ferguson, who missed New Mexico's shutout of Wyoming last week with a shoulder injury, ran for 86 yards and the Lobos used two quarterbacks to pass for 155 yards, but couldn't get a touchdown on the Cougars.
Bryant Williams took a 14-yard screen pass to the end zone, but tackle Byron Bell was called for a block in the back and the play was called back. Instead of getting within 14-10, the Lobos had third-and-21 and threw two incompletions to end the threat.
Bell jumped up and down protesting the call and replays showed he did not appear to hit the player who went down in front of him.
New Mexico coach Rocky Long was still livid about the call after the game.
"I don't know if we would have won or not, but the officials obviously blew a call that changed the entire momentum of the game. It is criminal that they changed the momentum like that," Long said. "We might have still lost the game, but it should have been a hell of a game right until the end and the officials took that away from us."
BYU got the ball back on downs and drove 75 yards to put the game out of reach on Hall's pass to Collie.
Smith was 5-for-10 for 69 yards and Brad Gruner was 8-for-12 for 86 yards.
James Aho scored New Mexico's only points on a 27-yard field goal with 11:40 left in the second quarter. Nobody had scored first on the Cougars this year.
BYU had just 45 yards in the first quarter and 175 yards at halftime. The Cougars punted on the first series of the third quarter, then got rolling after the defense forced the Lobos into a three-and-out. BYU got the ball back at its own 31 and on first down Hall threw it to Collie across the middle and the Cougars' leading receiver ran to the Wyoming 39 for a 30-yard gain.
Hall completed the drive a few plays later with an 11-yard pass to Andrew George, who hung on when he was hit right after the catch. It was the second touchdown of the day and third of the season for George.
The Cougars struggled through the first quarter, then Hall got the Cougars going with a 58-yard pass to Collie to New Mexico's 22 yard line. Harvey Unga got BYU inside the 1-yard line with four carries and on third-and-goal Hall rolled out and found George alone in the back of the end zone to cap the 95-yard drive and put BYU up 7-3 with 6:34 left in the second quarter.
BYU got the ball back when Gruner and Ferguson collided on a handoff and Jan Jorgensen recovered for the Cougars at the New Mexico 47. The Cougars reached the 17, but on first down Collie was called for offensive pass interference and the penalty pushed the ball back to the 32-yard line. Hall threw two more incompletions and BYU had to go for a field goal from 49-yards out and Mitch Payne's kick was wide left.
It was the lowest-scoring first half for BYU since the Cougars led Utah 3-0 at halftime last Nov. 24.
"I was happy the way they responded in the second half they responded in the way they needed to to win the football game," BYU caoch Bronco Mendenhall said.