TUSCALOOSA, Ala. -- No. 1 Alabama's defense shut down Auburn and its offense did just enough to win the 81st Iron Bowl.

The Crimson Tide (12-0) got three touchdowns from quarterback Jalen Hurts and a big receiving day from ArDarius Stewart en route to a 30-12 victory on Saturday.

Alabama won its third straight in the series and clinched its third undefeated regular season under Nick Saban.

"This was a great win for our team," Saban said. "I'm really proud of our team, especially the way that they played in the second half.

"We turned it around on offense and really dominated the game in terms of time of possession. We had some really good drives. We didn't always finish, but we really executed a lot better in the second half."

The Crimson Tide's defense continued its strong play to open the second half. Alabama forced a punt, which led to the Tide's second touchdown of the game, when Hurts found the end zone from 4 yards on a quarterback keeper to make it 20-9 early in the third quarter.

Alabama struck again in the third quarter with Hurts finding Stewart for a 38-yard touchdown pass to make it 27-9.

Late in the third quarter, Auburn kicker Daniel Carlson added his fourth field goal of the game to cut it to 27-12. But Alabama kicker Adam Griffith added a 30-yard field goal early in the fourth quarter to push the Tide's lead to 30-12.

"It was a tough loss for our team," Auburn coach Gus Malzahn said. "I am proud of our guys, the way they competed. Our defense played extremely well until they got worn down."

After forcing Alabama to punt, Auburn picked up a 58-yard punt return from defensive back Stephen Roberts to move inside Crimson Tide territory. But the Tigers couldn't take advantage of the great field position and lost yardage on the drive.

Alabama hasn't allowed a touchdown since the third quarter of the Texas A&M game on Oct. 22.

"I was really proud of the way the guys competed,” Saban said. "I can't tell you about the scoring touchdowns thing. I know our guys are very competitive and have a lot of pride, and they have played at a really high level -- especially in these past three or four games.”

Carlson booted a 42-yard field goal to give Auburn a 3-0 lead with 12:31 left in the first quarter.

On its ensuing drive, Alabama pushed down the field and made it to the red zone before tying the score at 3 on a 29-yard field goal with 5:40 left in the first quarter.

The Crimson Tide found the end zone after another Auburn punt. Hurts hit running back Damien Harris, who scampered in for a 17-yard touchdown to give Alabama a 10-3 lead late in the first quarter.

Early in the second quarter, Carlson drilled a 52-yard field goal to cut it to 10-6. The score came after Auburn defensive back Daniel Thomas intercepted a pass from Hurts to give the Tigers good field position.

Carlson was true from 39 yards late in the second quarter, cutting the Tigers' deficit to 10-9 with 3:30 left in the first half.

With less than 30 seconds left in the half, Griffith added his second field goal of the day. This time, Griffith connected from 25 yards to make it 13-9 Alabama at halftime.

"It really stands out to me that the time of possession is doubled," Malzahn said. "They just got worn down. Offensively, just didn't get first downs. Really just didn't get it done. You know, (we were) 2 of 12 on third downs, I really think that really caused the problem."

NOTES: Auburn started senior Jeremy Johnson at quarterback. Starter Sean White is dealing with a shoulder injury. Both Johnson and John Franklin III played in the game. White did not play. ... Alabama travels to Atlanta next Saturday to face Florida in the SEC Championship Game. The Crimson Tide won the SEC title the last two seasons. ... Alabama junior DB Tony Brown was disqualified for targeting late in the first quarter. ... Alabama CB Marlon Humphrey left the game in the second half and did not return. Alabama coach Nick Saban said he should be fine.