Auburn is making a run at SEC West sleeper. The No. 21 Tigers beat No. 17 Arkansas 56-3 Saturday night on The Plains.

The dominant performance featured Kamryn Pettway continuing his tear and a defense that held the Razorbacks (5-3, 2-2) to three points in the first half, their lowest total since 2013 and 32 points below average. It was Auburn’s largest margin of victory over a ranked team in school history.

Austin Allen, the SEC’s leading passer, left with a strained knee for a possession in the first half. He did return but finished with 187 yards on 17 of 30 passing with a pick. He didn’t play the fourth quarter and had his lowest yardage total and lowest QBR of the season.

To sum it up, Arkansas had 400-plus total yards in each of its first six games – 215 Saturday. Auburn (5-2, 3-1) had 543 rushing yards, its most since the 2013 SEC championship game. The Tigers had 632 total yards, 9.5 yards per rush and zero negative yardage plays.

What it means: Auburn scored 20 points only once in its first four games. The Tigers scored three touchdowns in the first quarter against Arkansas. Since Auburn coach Gus Malzahn handed play-calling duties over to Rhett Lashlee, the offense has blossomed. The Tigers had 688 total yards against Louisiana Monroe and 432 at Mississippi State.

Auburn had 335 total yards in the first half at Mississippi State two weeks ago. Following a bye, the Tigers had 328 in the first half Saturday. It’s Pettway but it is also quietly quarterback Sean White. White isn’t flashy and he is only eighth in the SEC in yards. But he is first in the league in completion percentage by more than six percentage points. He threw for 77 yards on 6 of 11 passing with a touchdown and ran for more 61 on four carries. His ran a play-fake to perfection on a fourth-down touchdown run in the third quarter.

What I liked: Kamryn Pettway continued his tear. The sophomore back rushed for 192 yards and two touchdowns on 27 carries. After 39 carries for 169 yards two weeks ago at Mississippi State, Pettway had 16 carries for 117 yards … in the first half. On a second-quarter run, the 240-pounder shoved off an arm-tackle effort from Josh Liddell. He picked right back up in the second half, running for 75 yards and a touchdown on 11 carries in the third quarter.

Kerryon Johnson wasn’t 100 percent but Auburn coach Gus Malzahn said he would have been able to go. Pettway again made that unnecessary.

“We just have to keep running the ball,” Malzahn told ESPN’s Holly Rowe at the half.

Pettway has taken over the team rushing lead and is quickly climbing up the top 10 in the SEC after a career night, his fourth 100-yard game of the year. When Johnson returns, it looks to be a deadly duo.

What I didn’t like: A couple of things for Arkansas. Defensive coordinator Robb Smith said the Razorbacks needed to limit explosive plays. That plan went by the wayside in the first quarter. Auburn scored on its first play, a 78-yard run from Eli Stove. On a drive that made it 14-0, White had a 41-yard run. The Tigers’ third touchdown of the first quarter was a 20-yard run from Stanton Truitt. A 28-0 lead came thanks to a 45-yard touchdown pass from White to Truitt. It got sillier in the fourth. Truitt added an easy 31-yard touchdown run and Kam Martin a 51-yard touchdown run.

Another thing not to like for Arkansas: In its two other losses, the Razorbacks had eight turnovers that led straight to points. An interception Saturday was cleaned because of an offsides flag but Allen’s lost fumble in the first quarter led to a touchdown. Javaris Davis picked Allen in the third quarter and Auburn scored on a Pettway run.

Who’s the man: Tough to argue with picking Pettway. Not only did he have a career-high, he did it on 27 carries with a 7.1 yard average in three quarters.

Key play: Auburn was already leading 35-3. Arkansas can score in bunches but its last gasp came in the third quarter. On fourth down, Carl Lawson beat his man into the backfield, forced Allen from the pocket and Davis made a bobbling interception.

What’s next: Auburn is at Ole Miss and Arkansas has Florida. If Auburn keeps winning, Nov. 26 will be a huge day in the state of Alabama, as well as the Playoff picture.