NEW ORLEANS - In the just over two months since LSU and Alabama last played, Alabama quarterback A.J. McCarron improved dramatically.

LSU's quarterback play? Not so much.

McCarron gave Alabama what it didn't have in an overtime loss to LSU on Nov. 5 by passing for 234 yards Monday, and Alabama's defense smothered LSU in a 21-0 win in the BCS National Championship Game at the Mercedes-Benz Superdome.

"The offensive line gave me time and I just put it in there and (the receivers) made plays," McCarron said. "I can't say enough abou that group."

Alabama kicker Jeremy Shelley tied a record for all bowls with five field goals and set an all-bowls record with seven attempts, stats that were all but separated No. 2 Alabama (12-1) from a complete rout of the home-state Tigers.

Trent Richardson scored the first touchdown in an LSU-Alabama game this season with a 34-yard fourth quarter run. Richardson rushed for 96 yards on 20 carries in the game. McCarron, the sophomore who was named the offensive player of the game, completed 23 of 34 passes for Alabama.

The passing game was what Aloabama lacked in LSU's , 9-6 overtime win at Tuscaloosa on Nov. 5, a game where McCarron looked like a sophomore.

Since the end of the regular season, McCarron certainly appeared to have grown up for Alabama. But he still wasn't engineering touchdown drives as an LSU defense that was on the field for 35:26 and for 69 plays managed to keep Alabama out of the endzone much of the night.

The Crimson Tide also played turnover-free offense.

"Give credit to them," LSU defensive back Eric Reid said. "They didn't give us opportunities to create turnovers."

While Alabama was kicking field goals, LSU (13-1) wasn't even close to sniffing points.

LSU managed just five first downs as Jordan Jefferson, who gained the starting job that he never relinquished for LSU in the first Alabama game was completely and utterly ineffective. Jefferson passed for just 55 yards and turned the ball over twice. He completed 11 of 17 passes, but all for short gains, except for one 19-yard pass to Odell Beckham, Jr.

LSU crossed midfield just once and not until the fourth quarter.

Jarrett Lee, the quarterback who lost his starting job to Jefferson Nov. 5, never had a chance to redeem himself Monday, watching the entire game from the sideline.

"We wanted to dominate from start to finish and that's what we did," said Alabama linebacker Courtney Upshaw, who was named the game's Defensive Player of the Game after recording seven tackles.

Alabama outgained LSU 384-92 as Alabama claimed the Southeastern Conference's sixth straight national championship, the second for Alabama in that stretch. It's also the third national title for Nick Saban, making him the first coach to win three BCS titles.

"I told my players I did not see it coming and it's my fault," LSU coach Les Miles said.