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Air Force backup quarterback Kale Pearson took just one snap against Wyoming, but it turned out to be the biggest and most controversial of the game.

Pearson scored on a 5-yard bootleg in the fourth quarter, lifting the Falcons over the Cowboys 28-27 Saturday night.

"The hardest part right there is just getting the snap," Pearson said. "Coming in, first play, you got your nerves goin', but actually I did my job, and I knew everybody else would do theirs."

Connor Dietz, who left the game for one play because of an injury, passed for 141 yards and two touchdowns for the Falcons (3-3, 2-1 Mountain West). Dietz rushed for 92 yards.

Wyoming coach Dave Christensen was visibly upset with Falcons coach Troy Calhoun after the game.

Christensen later questioned whether Dietz was injured, noting the quarterback walked about 20 yards before taking a knee near the Falcons sideline. He said the several minutes that trainers attended to Dietz gave Air Force time to strategize the next play.

"There was nothing wrong with that player, except that his helmet came off," Christensen said. "And I have a real problem with that."

About eight minutes remained in the game, and the Falcons had all three timeouts remaining.

Before Pearson entered, the referee announced that Dietz, by rule, had to leave the game because his helmet came off.

"In this game we're supposed to be ethical, and that's not ethical," Christensen said. "I don't know what they teach at Air Force, but I'm not going to teach that to my kids. I want my guys to get off the field when they're hurt, and we don't want to stop the game."

Calhoun declined to discuss incident in detail with media.

However, he described the conversation with Christensen as "probably not a conversation that I'd have with my mom . not that kind of dialogue."

Wyoming (1-5, 0-2) played without starting quarterback Brett Smith, who was scratched just before the game because of an undisclosed injury. Entering the weekend, Smith was ranked ninth in the nation in total offense, averaging 336 yards a game.

Smith was replaced by freshman Jason Thompson, who passed for 195 yards and a touchdown and rushed for 75 yards.

For the second straight week, Wyoming faced and held in check the nation's leading rusher.

Air Force running back Cody Getz, who entered averaging 177.4 yards a game, was held to just 41 yards on 10 carries. He left the game late in the third quarter with a lower left leg injury. The previous week, Wyoming held Nevada's Stefphon Jefferson, who was averaging 175.4 yards a game, to 78 yards.

The Falcons entered the game averaging 389.6 rushing yards a contest — second in the nation.

Wyoming held Air Force to 230 rushing yards on 51 carries.

But the Cowboys gave up two long TD passes — a 41-yard strike from Dietz to Don Strickland and 46-yard score from Dietz to Ty MacArthur.

Still, the Cowboys led 27-21 entering the fourth quarter, thanks to a 9-yard run by Shaun Wick, 4-yard TD pass from Thompson to Chris McNeill, 1-yard run by D.J. May and two field goals by Stuart Williams.

When Dietz was shaken up after being tackled on Wyoming's 5-yard line on a short run, Pearson came in on third and goal, faked a handoff and sprinted around the right end, diving for the pylon at the front corner of the end zone. He was initially ruled out of bounds, but a review of the play revealed that he got the ball over the pylon for a touchdown.

"I knew it was going to be close," Pearson said. "I knew it right when I turned around I would have to dive. I was just happy the coach had faith in me to run a bootleg."

Dietz returned on Air Force's next possession and finished the game.

Wyoming outgained Air Force 447-371 and had an 11-minute advantage in time of possession, but the Cowboys failed to score in the final quarter.

"We're going to be a squad that just has to gut, grind, strain and persevere, and that happened tonight," Calhoun said. "We came up with some huge, huge stops on defense in the second half."

Thompson, who completed his first nine pass attempts, failed to complete any of his three attempts in the fourth quarter. He finished 23 of 36 with no interceptions.