By Paul Newberry
The Associated Press

ATLANTA (AP) — With Jeremy Johnson taking over at quarterback, No. 6 Auburn looked a bit sluggish on offense.

Fortunately for the Tigers, Will Muschamp’s revamped defense came up with a couple of huge plays. The former Florida coach made his debut as Auburn’s defensive coordinator, charged with turning around a unit that fell apart late last season. The first half of the opening game was promising, with an interception leading to the Tigers’ first touchdown and Justin Garrett scoring on an 82-yard fumble return.

“I am very excited about this season and what the defense can do,” tackle Montravius Adams said. “We forced a lot of turnovers and got a lot of sacks. That shows people we are getting better.”

Even though he spent the last two years behind Nick Marshall, Johnson came into the season hyped as one of the potential breakout stars in coach Gus Malzahn’s explosive spread offense.

The junior completed only 11 of 21 for 127 yards with three interceptions, though he did throw a 33-yard touchdown pass to Ricardo Louis.

“I just made some mental mistakes,” Johnson said. “I’ll learn from it.”

Peyton Barber, taking over after starter Roc Thomas went out with an undisclosed injury, wound up carrying the bulk of the offensive load in the Chick-fil-A Kickoff Game at the Georgia Dome. The third-year sophomore rushed for 115 yards on 24 carries — double his career output.

“That meant everything to me,” Barber said. “This is what I’ve been waiting on.”

After not naming a starter at quarterback, Louisville pulled a surprise by giving freshman Lamar Jackson the bulk of the snaps over three more experienced players thought to be battling for the job. Coach Bobby Petrino sent out both Jackson and sophomore Reggie Bonnafon for the first play, a trick formation the team had been working on all week. Bonnafon went in motion but the direct snap was botched, leaving Jackson scrambling to his right. Looking very much like it was his first college play, he simply threw it up, right into the arms of Tray Matthews.

The Auburn safety returned the interception 35 yards to the Louisville 26, setting up Johnson’s 1-yard touchdown run.

Bonnafon played into the second quarter before giving way to Jackson for good after a fumbled handoff with Louisville driving gave the Tigers a 14-0 lead. Garrett scooped up the loose ball and took off the other way, with Muschamp running with him nearly stride for stride along the sideline.

“I saw the ball squirt out,” Garrett said. “I just tried to pick it up and run back to the house with it.”

Jackson did plenty of good things for the Cardinals in his debut. He was only 9 of 20 passing for 100 yards, but led the team in rushing with 106 yards on 16 carries, including a 10-yard touchdown toward the end of the third quarter.

“That freshman quarterback is electric,” Malzahn said. “He’s going to be tough to deal with.”

Auburn will host Jacksonville State next week at 11 a.m.