TUSCALOOSA, Ala. -- It started -- and ended -- with a fake punt.
Top-ranked Alabama outfoxed LSU with a fourth down conversion early in the third quarter and ran off 21 straight points for a convincing 38-17 win on Saturday night.
The Tide (9-0, 6-0) took a giant step toward the SEC and BCS title games with the win. LSU (7-3, 3-3) was eliminated from contention in the conference.
T.J. Yeldon did the heavy lifting for Alabama, picking up 133 yards and two touchdowns on 25 carries. Kenyan Drake added 65 yards on the ground, and A.J. McCarron threw for three touchdowns, completing 14 of 20 passes for 179 yards.
LSU quarterback Zach Mettenberger completed 16 of 23 passes for 241 yards and a score. He hooked up with Jarvis Landry five times for 90 yards. Only 68 of those yards came after the break, however, as Nick Saban's defense showed why it's considered the nation's best.
"I was really proud of our players in the second half," Saban said after watching his team give up just 52 second-half yards. "I thought they did a fantastic job and probably played our best half of football."
Trailing 17-14, LSU quickly evened the score with a six-play, 50 yard drive to start the second half, capped off by a 41-yard Colby Delahoussaye field goal.
From there, though, it was all Alabama. On the Tide's first drive of the third quarter, Jarrick Williams ran for six yards on a fake punt to convert a fourth and two from the Alabama 41, fueling a 79-yard scoring drive.
"I just got the ball, saw an opening and took it," said Williams, a cornerback. "I gained six yards for my team."
His team took a 24-17 lead it would not relinquish on a Yeldon's 4-yard touchdown with 4:11 to play in the quarter, using 14 plays -- including 12 runs -- and eating up 7:50 in the process.
When LSU's following drive stalled near midfield, Alabama went back to the ground. Yeldon, again the bell cow, totaled 48 yards, the final one coming on a touchdown run to give Alabama a 31-17 advantage with 10:31 left in the game.
"Those two drives were long and ate the clock up," Miles said. "Suddenly, it's 14 points with a sudden need to make things happen."
Odell Beckham Jr. seemed to supply some urgency to LSU's sideline when he took the ensuing kickoff 82 yards to encroach Alabama's red zone. But there the Tide stood firm, forcing a loss of 3 yards and three incomplete passes -- the last on a desperation fourth-and-13 -- to turn the Tigers over on downs.
Saban would show no mercy. Happy to hand the ball to Yeldon, Alabama marched 78 yards in seven plays -- helped in no small part by two LSU personal fouls -- for the final score, a McCarron pitch to Jalston Fowler from the three to cap off another clinical drive.
LSU stalled on its final drive, which ended with three straight sacks. The Tide held the Tigers to just 52 second half yards, including minus-16 rushing.
"They did a good job of scheming all over," said LSU running back Jeremy Hill, who gained just six of his 42 yards on the ground in the second half. "They made the right adjustments."
Both LSU and Alabama moved the ball all over the field for the first 30 minutes, but when the Tide couldn't stop the Tigers, the Tigers stopped themselves.
LSU seemed set to take an early lead when Mettenberger hit wide receiver Landry for a 45 yard completion to the Tide 31.
But three Tiger runs and 27 yards later, Alabama linebacker Tanna Patrick forced a fumble from fullback J.C. Copeland near the goal-line and Alabama safety Landon Collins picked it up at the 10.
"You can't turn the ball over," LSU coach Les Miles said. "It just cost us a terrible start."
After their offense punted, the Tide defense took advantage of another LSU turnover, as Trey DePriest fell on a premature snap by LSU center Elliiot Porter at the Tigers 27. Alabama's offense stalled and settled for 41-yard field goal from Cade Foster with 3:54 left in the first to open the scoring.
LSU responded quickly, converting two third downs through the air to set up a Jeremy Hill punched 3-yard rushing touchdown on the first play of the second quarter in for a 7-3 advantage.
LSU would not lead again. McCarron took advantage of a third down pass interference penalty by finding tight end O.J. Howard, who took a short slant 52 yards for a 10-7 edge.
A tightened Tide defense, which gave up 129 first-quarter yards, quickly forced LSU off the field, and Saban's offense drove 80 yards on 10 plays, pushing the lead to 17-7 with 5:19 left in the half on a 9-yard McCarron toss to wide receiver Kevin Norwood.
Not to be outdone, Mettenberger engineered a scoring drive of his own, marching 75 yards in 10 plays. His 6-yard toss to wide receiver Travin Dural on third-and-goal -- the last of three third down conversions on the drive -- completed the first-half scoring, but LSU would not cross the goal line again.
"It's not fun to finish second," Miles said, "and today we finished second."