It was only halftime.

The No. 3 Oklahoma Sooners steamrolled the Aggies 54-3 Saturday. The game was out of hand before the first half was over. By that time, Oklahoma had piled up 38 points and 412 yards. Utah State had three points and 62 yards.

The big plays made the difference, said Utah State coach Brent Guy. OU had five touchdowns of more than 25 yards, including two touchdown runs of more than 50 yards.

"Obviously, we didn't give them any type of game that we wanted to play out there," Guy said. "We're really disappointed with the big plays because that was the thing that we worked on a lot and something we're really concerned about."

Guy said the game had three back-breaking plays that did his team in.

The first was getting Oklahoma into a third-and-17 situation before allowing a 19-yard completion on the next play.

The second was when the Aggies had the ball at midfield, but fumbled it to the Sooners.

The third came in the third quarter when Utah State pinned Oklahoma on the 4-yard line after a rolling punt from Leon Jackson. On first down, Oklahoma's DeMarco Murray ran for four yards up the middle. On his next run, he went 92 yards down the sideline for a touchdown.

Guy said Oklahoma's talent and speed played a role in the big plays, but that doesn't mean his players can't make open-field tackles.

The Aggies struggled on offense, mustering only 153 yards compared with the Sooners' 617. It was the first time the Aggie defense allowed more than 600 yards since allowing 654 against Louisiana-Monroe in 2002.

Jackson started at quarterback for Utah State, but rotated with Jase McCormick in spots. McCormick came in early in the game, which is something Guy said he planned to do.

"At that point in the game, we were getting outmatched, and [offensive coordinator Darrell Dickey] wanted to put him in there to see how he'd do under these situations and under this pressure," Guy said.

He added that he wanted McCormick to get experience should Jackson get hurt.

McCormick said he was told at the start of the week that he'd get snaps in the third or fourth series.

Jackson finished 9-for-14 for 65 yards while McCormick was 6-for-10 for 22 yards. It was McCormick, though, who led the Aggies on a 10-play, 46-yard drive that ended with a 30-yard field goal from Peter Caldwell - the Aggies' only points of the game.

McCormick said the big plays doomed any chance for the Aggies, especially in the environment.

"To compete with a team like this, we have to do the things it takes to get that momentum."