The LSU defense had its worst start and best finish of the season in Saturday’s 27-23 victory against then-No. 10 Auburn at Tiger Stadium.

The Tigers’ D was practically helpless in the first quarter as Auburn gained 188 yards and built a 17-0 lead. It was marginally better in the second quarter as Auburn headed to halftime with a 23-14 lead.

But in the second half, LSU’s defense dominated. LSU allowed just 58 rushing yards on 19 carries after halftime as Auburn finished with a 4.3 average on 44 carries. Jarrett Stidham, who started 6-of-8 for 144 passing yards, finished 9-of-26 for 156.

Auburn had scored in 18 consecutive quarters -- including three full SEC games and Saturday's first half -- until LSU shut out the Tigers in the second half.

Overall in the second half, Auburn ran 32 plays for 64 yards.

On third down, Auburn converted 3-of-14 and failed on both of his fourth-down attempts.

“It’s a tough scheme to stop,” LSU defensive end Rashard Lawrence told NOLA.com/The Times-Picayune. “We had to just settle down though. We were missing a lot of open-field tackling and we practiced all week on tackling. Once we settled down and started coming downfield, it was different.”

The LSU defense obviously got better as the game went along and there’s reason to think that trend might continue.

Linebacker Arden Key had his biggest impact in his four games since returning from off-season shoulder surgery. He had his first full sack of the season on Auburn’s final offensive play.

Lawrence, who has dealt with two ankle injuries, is gradually getting healthier. He had five tackles as he continues to increase his workload.

Fellow end Christian LaCouture had an impact for the third consecutive game, finishing with seven tackles.

Both Lawrence and LaCouture benefited because defensive end Frank Herron made his season debut after being sidelined for an undisclosed reason. Herron’s presence also allowed Greg Gilmore to stay put at tackle and he contributed seven tackles, including a sack.

Herron didn’t record a stat, but he helped keep other ends fresher and as time goes along he figures to play more and make more plays.

Speaking of making plays, linebacker Devin White continues to do so consistently. He had a team-high 15 tackles, marking his fifth consecutive game with at least 10.

The secondary had one of its best games despite a first-quarter breakdown that yielded a 49-yard touchdown pass for Auburn.

LSU finished with 11 pass breakups. Greedy Williams, who leads the team with three interceptions, had just one pass breakup, but it was a key one in the end zone. Cornerback Kevin Toliver II had two breakups, as did safeties Eric Monroe and Grant Delpit.

Cornerback Donte Jackson, who teams have generally avoided this season, responded when Auburn attacked his side. He had four pass breakups, including one dropped interception on Auburn’s last possession.

LSU is second in the SEC in completion percentage allowed at 54.4 after Auburn's Jarrett Stidham went 9-for-26 on Saturday.

“I was thinking about taking it to the house and putting the dagger in their heart,” Jackson told NOLA.com/The Times-Picayune. “It didn’t work out that way.”

The LSU defense, like the team as a whole, has had its ups and downs. It was outstanding against BYU and solid against outmanned Chattanooga to start the season. It got pushed around by Mississippi State, struggled against Syracuse and was surprisingly ineffective against Troy.

But it clamped down on Florida to secure a one-point victory on Oct. 7 and its second-half shutout was necessary in the comeback against Auburn.

It’s still a work in progress, but coordinator Dave Aranda has more tools to work with now. This Saturday he will need them against Ole Miss and quarterback Shea Patterson, who will test the pass defense more than anyone else has so far.