BATON ROUGE, La. — As the Alabama football team buses rolled up to Tiger Stadium on Saturday night, the booing started.

Then the Crimson Tide's head coach, Nick Saban, stepped out. The reaction went up a notch or two. Saying the crowd of LSU purple-and-yellow clad fans booed him is like saying the Pacific Ocean is deep.

There was no love for the coach who brought LSU a national title in 2003 when he coached the Bengal Tigers.

It wasn't the last disagreeable moment for Saban during the night.

His Crimson Tide trailed for much of the fourth quarter and the offense struggled almost the entire second half.

But the night ended pleasantly for Saban after T.J. Yeldon scored on a 28-yard screen pass with 51 seconds left to give Alabama a 21-17 victory and keep its national championship hopes alive. The winning score culminated a 72-yard drive.

"What we talked to our team about was we would have to overcome adversity," Saban said afterward. "So what we said when things went bad and sideways, we would have to overcome adversity."

Alabama (9-0) entered as the No. 1 team in the country, needing only to win out for the rest of its schedule to reach the national title game for the second straight year. No. 5 LSU dropped to 7-2.

"Coach preaches that every game is going to be 60 minutes," Tide quarterback AJ McCarron said. "It was a huge win and an unbelievable win."

A one-loss SEC team may not be able to make the BCS championship game because three other 9-0 teams from the AP top 10 remain eligible for the game — No. 2 Oregon, No. 3 Kansas State and No. 4 Notre Dame, which survived three overtimes to defeat Pittsburgh on Saturday. No. 6 Ohio State (10-0) isn't eligible for the BCS title game.

The road doesn't get any easier for Alabama. The Crimson Tide will return home to face Texas A&M on Saturday. The Aggies, led by freshman quarterback Johnny Manziel, have won six of eight games this year. The losses came by a combined eight points to Florida and LSU.

Alabama will represent the SEC West in the league championship game Dec. 1 in Atlanta if it wins one of its final two SEC games. The Tide plays Auburn on Nov. 24 in Tuscaloosa.

If Georgia wins its final SEC game Saturday at Auburn, it will represent the East in Atlanta.

Saban also won his previous game against LSU, denying the Tigers a national title in January.The rematch came Saturday night, with the nation watching in a prime-time television broadcast by CBS. LSU also gave out a school-record 947 media credentials to this one. ESPN broadcast not only its popular "Gameday" television show from the LSU campus but its "Gameday" radio show as well.

The LSU students packed their section in Tiger Stadium more than an hour before kickoff. The game even drew the celebrity factor — filmmaker Spike Lee, who always seems to latch onto whatever sporting event or team is hot at the moment, showed up on the sidelines with neon yellow jacket and shoes.