Three short months ago, Tanner Mangum returned to the United States from his mission in northern Chile.

"It's a little bit different than Memorial Stadium in Lincoln, Nebraska," said Mangum, whose 42-yard Hail Mary pass to Mitch Mathews snatched victory from Nebraska's grasp Saturday afternoon.

The 22-year-old freshman was called into action when senior starter Taysom Hill left the game with a foot injury that coach Bronco Mendenhall said would likely end his season.

"It's been a while since I felt that. My last competitive football game was the Under Armour All-American Bowl on Jan. 1 2012, and before that was the state championship (in Eagle, Idaho) in 2011," Mangum said. "It was a blast. It was so fun being out there playing again. To play in that environment, in front of 90,000 fans. It was like going back, playing in my backyard again."

It seemed that way to Mathews as well.

"I don't even know what the play is called," the senior wide receiver said. "I looked to the sidelines and they said just take off into the right corner of the end zone. With 48 seconds left (when the drive started), we knew what we had to do."

Mathews said he, Nick Kurtz and Terenn Houk flew toward the end zone, with Mathews going diagonally across the field.

"I had three incredible receivers to throw to and the offensive coordinator just told me to buy some time, throw it up and let the guys make a play," Mangum said. "So I rolled out and threw it.

"It wasn't my best ball. It came out a little wobbly, but I was just glad it got there. Mitch made a heck of a catch and was able to fall in for the score."

Nebraska wrenched control of the game from BYU with a strong third quarter, taking a 28-24 lead on a touchdown pass from Tommie Armstrong to Trey Foster.

With a gimpy Hill at the helm, the Cougars twice had to punt before Mangum took over in the final period and guided BYU to a 35-yard field goal by Trevor Samson.

After Nebraska's Drew Brown missed a 41-yard field goal with 48 seconds to play, Mangum looked like a veteran. He ran for 11 yards before Adam Hine picked up 16. Mangum ran for 7 yards to the Nebraska 49-yard line, and with six seconds left, threw an incomplete pass to Mathews.

"Actually, he caught it, but he was out of bounds and we had a second left," Mangum said.

Mendenhall made the situation clear.

"The last thing I said to Tanner was the play before the Hail Mary and I said to make sure that you throw it on time so we can have one more shot," the coach said. "After the incomplete pass, we thought it would be better to throw it in the end zone than to kick a long field goal. We were about 5 yards out of that range."

Mendenhall said Mangum's freshman designation might be misleading.

"It wasn't a question of ability or capability. It was just a question of how long he could go because he's been back from his mission for such a short amount of time," he said. "We have to help him make it through the year now, but what a great way to start, coming off a mission as a freshman and then throwing a Hail Mary to beat Nebraska.

"Victory and defeat hangs in the balance on the result of one play. I know what defeat feels like and I know what the win looks like. To be at the mercy of that and watching the play, there's no more raw emotion than a setting like that."

Mendenhall said he felt badly for Nebraska coach Mike Riley.

"My heart goes out to him and the team. He's a good friend of mine and a really good person and a really good coach," Mendenhall said.  "Nebraska played really hard right to the end and so did we. Sometimes, one play determines a game."

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