By MATT BECKER
(AP) -- Although Tennessee faced the nation's top-ranked team last weekend, coach Derek Dooley feels an even bigger challenge lies ahead with Alabama.
Visiting the second-ranked Crimson Tide on Saturday night, the Volunteers try to overcome the nation's No. 1 defense and slow down a running back emerging as an early Heisman Trophy favorite. No opponent has come close to accomplishing either task.
Alabama (7-0, 4-0 SEC) is outscoring opponents by an average of 32.7 points and hasn't won a game by fewer than 16. Last Saturday's 52-7 win at Mississippi was its highest-scoring conference game since 1990.
The defense came out a little flat, giving up 72 yards on the Rebels' first possession, before buckling down and yielding 69 the rest of the way. The 141 yards were its fewest allowed to an SEC opponent since giving up 103 to Mississippi State in 2005.
It turned out to be another dominating performance by Nick Saban's team, which ranks first in the FBS in total defense (184.1 yards per game), run defense (38.1) and points allowed (7.0 per game).
"It's his best team," said Dooley, who coached under Saban at LSU and with the Miami Dolphins. "Probably as physically a dominating defense as I've seen in the modern era of football and I know that is a strong statement, but I believe it. Incredible talent at every position, great coaching and just a relentless, physical dominating style of play.
"It's a great football team. Like I told the team you only get 12 days to compete, 13 if go to a bowl game. We have to relish the opportunity to play against this type of football team."
The Volunteers (3-3, 0-3) had that kind of opportunity last Saturday and were blown away by top-ranked LSU, falling 38-7. This is the first time in school history Tennessee, which has lost eight straight and 14 of 15 to Top 25 teams, will face the nation's two highest-ranked teams in successive weeks.
The Vols were competitive early against the Tigers, holding them scoreless through one quarter and trailing 17-7 at halftime, but were overmatched in the second half. They finished with a season-low 239 yards, and Matt Simms looked shaky in his first start of the season.
Replacing Tyler Bray, who broke his thumb in a 20-12 loss to Georgia on Oct. 8, Simms was 6 of 20 for 128 yards and two interceptions. Simms was making his first start since completing 12 of 22 for 117 yards with an interception in last season's 41-10 loss to then-No. 7 Alabama.
The Crimson Tide have won four straight over the Volunteers since No. 7 Tennessee defeated unranked Alabama 16-13 in 2006. This is their longest winning streak in the series since reeling off seven in a row from 1986-92.
While the Volunteers will likely have their hands full trying to move the ball on Alabama's vaunted defense, they may have just as big a challenge when the Tide have possession.
Alabama amassed a season-high 615 yards last weekend, and most of the talk following the victory was Trent Richardson's highlight run.
The junior finished with career highs of 183 yards rushing and four touchdowns - including a 76-yarder in which he eluded three players at the line of scrimmage, then raced downfield and used another stutter step at the 10-yard line to beat the last defender.
"First of all, you look at him and he's physically imposing," Dooley said. "He is thick, you look at his legs and he has been gifted physically. He has an ability to play low to high, so he is always playing with power."
Richardson ranks second in the FBS with 912 rushing yards, is tied for third with 15 TDs on the ground and has matched Shaun Alexander's 12-year-old school record with six consecutive 100-yard rushing performances.
"Trent's a great player," Saban said. "He's one of the best players in the country. Whatever awards they give at the end of the season, he certainly should be considered for any and all of them that he qualifies for. But for right now, we're thinking about what we need to do right now. We're not even concerned about that stuff."
Richardson rushed for 119 yards on 12 attempts with a 65-yard TD against the Volunteers last season, and now faces a Tennessee defense ranked eighth in the SEC against the run, allowing an average of 155.8 yards.
Updated October 18, 2011