It was excellent preparation for Alabama.

Auburn made LSU play the way it used to play, the way it’s going to have to play against Alabama in 2 weeks.

Yeah Joe Burrow threw 42 passes and the LSU passing offense did plenty in the No. 2 Tigers’ 23-20 victory over the No. 9 Tigers on Saturday in Tiger Stadium.

But LSU had to turn back the clock a bit in order to hold off Auburn. And it should be grateful.

Ed Orgeron said during the week that Auburn had the best offensive line and the best defensive line that his team would have faced pre-Alabama.

He was right.

The game was physical. Auburn’s defensive line pressured Burrow early, though it never rattled him.

Auburn’s offensive line created enough running room for 130 rushing yards, but that was more than 100 fewer than Auburn’s SEC-leading average, and 70 of those yards came on one play.

It wasn’t that either Auburn line beat either LSU line for 60 minutes. Neither did.

It was that both Auburn lines challenged both LSU lines unlike they had been challenged previously.

And LSU was up to the task.

Burrow completed 32-of-42 for 321 yards with 1 touchdown and 1 interception.

But more important, Clyde Edwards-Helaire rushed 26 times for 136 yards and a touchdown. He took over on LSU’s most important possession of the game.

Here’s the context:

LSU was trailing 13-10 in the 3rd quarter, its first 2nd-half deficit of the season. It faced a 4th-and-goal from the 2 and Orgeron opted to go for the touchdown. Burrow’s pass to Ja’Marr Chase gained just 1 yard and Auburn took over.

But the LSU defense forced a punt and Burrow and Co. took over at the Auburn 45.

Suddenly it was as though Orgeron and offensive coordinator Steve Ensminger told passing game coordinator Joe Brady to take a break.

Edwards-Helaire ran for 22 yards. Then he ran for 12. Then he ran for 5, then 6 and a touchdown and a 16-13 lead that LSU would take into the 4th quarter.

LSU rode Edwards-Helaire the way it has ridden Burrow and the passing game for most of the season. As the 2nd half wore on the Auburn defense looked exhausted while Edwards-Helaire seemed fresh.

After Burrow ran 2 yards for a touchdown and a 10-point lead early in the 4th quarter the game seemed practically out of reach for Auburn even though 2 scores in nearly a full quarter is manageable.

But it seemed an overwhelming task because of the way the LSU defense was playing.

A D.J. Williams cutback on Auburn’s first possession of the 2nd half produced a 70-yard run to the LSU 9.

But LSU forced a field goal and a mere 13-10 deficit. Auburn’s next 6 possessions ended with punts and the first 5 possessions consisted of a total of 16 offensive plays.

When Auburn finally managed a 2nd-half touchdown that cut the lead to 23-20 with 2:30 left, it mattered little when LSU recovered the ensuing onside kick.

In the end, LSU won the game the way LSU used to win games – primarily by running the ball consistently well and playing stifling defense.

The difference is this team can lean on its passing game as it did periodically Saturday – or more substantially, as it generally has this season.

Against Alabama, Burrow and the passing game will be hugely important.

But Alabama is built like Auburn on both lines of scrimmage.

LSU won’t beat Alabama unless it’s also able to run at Alabama and have success. It won’t beat Alabama unless its defense can get stops – probably not as frequently as it did against Auburn, but at crucial moments.

There are concerns that might be significant: too many penalties, poor special teams, injuries to Grant Delpit and Derek Stingley Jr.

We’ll see how all that plays out over the next 2 weeks.

But during the first 7 games of the season, as good as LSU had been, concerns about LSU’s ability to get physical and run the ball at an elite front and to play the type of defense it generally has been known for against a top 10 team have been masked by the passing game’s video-game numbers.

Auburn forced LSU to show it can win the old-fashioned way.

LSU passed that test.

Next comes the ultimate test.