Playing with a sophomore quarterback who was making his first collegiate start, Auburn was right where it wanted to be with five minutes left in the first half of Saturday’s game with LSU.

Down only 7-3 to the nation’s No. 1 team at that point, Auburn coach Gene Chizik saw the game change in the blink of an eye when LSU struck for two long scoring passes before halftime and went on to crush his team 45-10 before 93,098 fans in Tiger Stadium.

LSU eventually scored touchdowns on its first two possessions of the second half and added a touchdown on an interception to cap a 35-point barrage in a span of 12 minutes, 33 seconds.

All told, 19th-ranked Auburn turned the ball over twice, including an interception return for a touchdown by LSU cornerback Ron Brooks, and gave up six sacks. Chizik’s team also committed at least one critical penalty on each of LSU’s three first-half scoring drives that produced a comfortable 21-3 lead.

“We did all the classic things on the road that you can’t do to win a game,” Chizik said. “On the road, as I’ve said all along, our margin for error is zero.

“We’re not good enough for negative things to happen to us and consistently overcome it. We had three critical penalties on drives that were going to get those guys behind the chains, or at least would have been a favorable possession that created points for the other team.”

It all started when LSU backup quarterback Jordan Jefferson fired a 42-yard scoring pass to wide receiver Rueben Randle, who easily eluded cornerback Robinson Therezie’s bump-and-run attempt at the line of scrimmage and sailed down the right sideline to make the catch with 5:00 left in the half.

After LSU’s defense held, Randle burned cornerback Chris Davis for a 46-yard scoring catch, this one from starting quarterback Jarrett Lee, to extend a once-precarious 7-3 lead to 18 points with 40 seconds to play.

“That’s how they beat people; they beat them with big plays,” Auburn defensive coordinator Ted Roof said. “That was one of our goals going in: not to give up big explosive plays in the passing game. On those two balls, they executed, they protected, they made the throws, they made the catches.”

The first touchdown was particularly frustrating because Auburn had LSU in trouble early in the drive.

Jefferson dropped the ball when running back Michael Ford accidentally knocked it out of his grasp and recovered for a 5-yard loss that would have brought up third-and-15 from the LSU 35.

But Auburn defensive tackle Kenneth Carter was flagged for grabbing Jefferson’s facemask to give LSU a new set of downs and two plays later, Randle got behind Therezie with safety Demetruce McNeal desperately trying to get over to help.

McNeal said he recognized the play and knew Jefferson was going to take a shot down the field. But when Therezie failed to slow down Randle, it was all over.

“I tried my best to get down the field, but by the time I got there, he was already putting the ball in the end zone, and there was no way I was going to catch him,” said McNeal.

Another penalty on the next drive, this one a pass interference call on Davis against Randle on third-and-5, kept the drive going.

“(LSU) stayed on the field on third down with penalties and after that they scored,” McNeal said. “They capitalized on that, and that was a big reason they got 14 points off the two big bombs. We said all week that we had to eliminate big plays, and they got two of them and that set the tone.”

Like Chizik, Roof pointed to the penalties as being critical to LSU’s five-minute surge just before halftime.

“We were in a pretty good rhythm … the kids were seeing the game well, they were tackling well,” Roof said. “Then, (LSU) had the big plays. They are tough to overcome, especially when they have the great defense they’ve got as well.”

In the second half, the home-standing Tigers continued the onslaught.

LSU got a 10-yard TD pass from Lee to Russell Shepard, then traveled 22 yards to a 1-yard Kenny Hilliard touchdown run. That score was set up after Auburn’s Tre Mason fumbled the kickoff following Shepard’s scoring catch on a big hit by LSU safety Eric Reid.

Auburn completely unraveled on its next series when Clint Moseley, who was 12-of-20 for 145 yards but was sacked six times, was intercepted by Brooks. He raced 28 yards untouched to the end zone for a 42-3 cushion with 7:27 to play in the third quarter.

Moseley, a native of Leroy, Ala., said he thought the pressure he’d seen at Sweet Water High School was bad enough until Saturday.

“This is a whole ’nother league,” he said. “They put the pressure on and got to me a few times. But I’ve never been under that kind of pressure before.

“There’s obviously plays I wish I had back,” Moseley added. “All I can think about is the negative plays I made, and I’ll do the best I can to get that corrected. The first start, you can use that as an excuse if you want to, but that doesn’t work with me. It doesn’t make me feel any better.”

It didn’t make Chizik feel any better, either.

“That was an anemic job of protecting the quarterback,” he said. “When you give up six sacks and can’t run the football, you have a hard time winning. That’s what happened today, and that’s why we lost.”