BATON ROUGE — It must have seemed like a dream the first 30 minutes, particularly for a much criticized and often belittled LSU defense.

But when LSU escaped a near-frozen Tiger Stadium for halftime respite Saturday, defensive coordinator John Chavis wasn’t satisfied.

“It’s not the scheme,” he yelled at his defenders. “It’s the great effort and energy of the guys that are playing for LSU.”

So No. 18 LSU promptly went out and topped the first-half effort, shutting out Johnny Manziel and high-powered Texas A&M in the second half as the Tigers pounded their way to a 34-10 victory over the No. 9-ranked Aggies.

“We really needed this to get back to what we’re used to,” LSU quarterback Zach Mettenberger said.

LSU, which led 21-10 at the half and dominated the second half, bounced back from a disheartening loss to Alabama in a big way.

“It left a bad taste in our mouths,” said Mettenberger, who threw two touchdown passes.

But that wasn’t the big story.

“Hats off to that defense,” LSU head coach Les Miles said. “That’s the kind of defense we’re used to.”

Well, maybe in years past.

But for this previously struggling LSU defense to hold the Southeastern Conference’s best offense to a fraction of its usual output came out of the blue — maybe the blue-norther that engulfed Tiger Stadium for LSU’s most impressive victory of the season.

“It was the best performance of this defense so far,” Miles finally admitted. “They were swarming all over the field.”

The Aggies and their up-tempo offense had scored at least 40 points in every game while averaging 578 yards.

Saturday they were fortunate to get 10 points and 299 yards.

“We weren’t able to stay on the field offensively,” said Texas A&M coach Kevin Sumlin. “We couldn’t make enough plays offensively to get in any sort of rhythm. They stuck to their plan.”

“You set your plan and you stick to it,” Miles said by way of an explanation. “You practice it and you tell them that’s what its going to be like. When it starts to go that way, they start to say ‘I got this.’ And that’s what happened.

“We didn’t turn the ball over, we got movement at the point of attack. They defense rushed and maintained leverage and we covered them. It goes on and on.”

Simple plan, but no other defense had put the stops on the Aggies like this.

Manziel’s day was a particular nightmare, as he completed 16 of 41 passes — the first time in his career he’s hit on fewer than 50 percent — and was intercepted two times by the Tigers and sacked twice more.

“They have a very talented defense regardless of how their season’s gone,” said Manziel, who may have seen his hopes of winning a second Heisman Trophy disappear on this national stage. “I think they came out and played a heck of a game. We could never really get it going.”

But the Tigers (8-3, 4-3 SEC) didn’t think they shut down Manziel as much as they minimized him.

“He can’t do much when he’s on the sidelines, that’s what we were thinking,” said LSU running back Terrence Magee.

And it wasn’t just the weather that kept Johnny from coming out to play — LSU had a 40:19-19:41 advantage in time of possession

Magee had a career-high 149 yards rushing as LSU ran for 330 yards and converted 11 of 17 third downs.

“We knew what we were getting into,” said A&M defensive tackle Julien Oioha. “They’re a run-run-pass team. We stressed that Mettenberger couldn’t get the ball to (Jarvis Landry) and (Odell Beckham). I think nearly every third down it seemed like it was those two receivers.”

Mettenberger was an efficient 11 of 20 for 193 yards, including a pair of third-down touchdown passes of 40 and 10 yards, both to Landry.

In the second half, with A&M (8-3, 4-3) trying desperately to get back in the game after the Tigers led 21-10 at the half, the Tigers controlled the clock for 22:30 to 7:30 for A&M.

“That’s the recipe for victory,” Miles said. “Offensively we were playing efficient football. That defense was going to get them stopped and we were going to possess the ball, to drive the ball.”

Jeremy Hill added 76 yards on the ground and Alfred Blue 61.

“When they’re running eight or nine men up in the box (to stop the run) and we were still able to run effectively, that’s awesome,” Mettenberger said. “And the only time I was touched all day it was a late hit (for a penalty).

“The big guys (offensive linemen) really took this game as a challenge. They showed you what they can do. That offensive line came to play.”

Texas A&M quarterback Johnny Manziel scrambles to avoid a tackle by LSU defensive tackle Anthony Johnson in the first half Saturday in Baton Rouge. The No. 18 Tigers beat the ninth-ranked Aggies 34-10. (Associated Press)

Gerald Herbert