KNOXVILLE, Tenn. — For three quarters of its 58-21 win at Tennessee on Saturday, Alabama’s defense looked as dominant as it has all season.

On the Vols’ third offensive play of the game, Alabama safety Xavier McKinney drilled Tennessee quarterback Jarrett Guarantano on a blitz and forced a fumble, which the Crimson Tide recovered at the 3-yard line.

The Volunteers followed that with two more three-and-outs and finished the first quarter with six offensive yards.

But then, as has been customary this season, the opposing offense began to heat up, putting points on the board by converting some chunk plays.

“Honestly I think as a defense we got kind of lackadaisical,” McKinney said. “We were on them pretty good the first [quarter] of the game. We had good momentum; we let them get a couple big plays and we lost the momentum that we had.”

Guarantano exited the game early in the second quarter after being knocked to the ground by an unblocked Mack Wilson. Backup quarterback Keller Chryst entered in relief, and completed five of his first seven passes for 26, 10, 23, 40 and 20 yards.

“We’ve got to be able to maintain that kind of intensity in the game,” coach Nick Saban said. “In the second quarter I didn’t think we played very well. They scored two touchdowns and we gave them an opportunity to get back in the game. … They had a really good plan against us; they had us a little confused in the second quarter.”

Tennessee wide receiver Jauan Jennings became the first player to record 100 receiving yards against Alabama since last year’s Iron Bowl. Seventy-four of his yards came in the second quarter, as did 63 percent of the Vols’ offensive yards.

The two touchdowns the Vols scored in the second quarter helped them score their most points against Alabama since 2003 — although seven of those came on a pick-six in the third quarter.

Aside from those two possessions, though, the Crimson Tide defense was suffocating, particularly at stopping the run. It allowed 31 rushing yards on 30 carries, and 20 of those yards came in the game’s final five minutes against the second-team defense. Tennessee had negative rushing yards for most of the game and didn’t get back into the positives until the end of the third quarter.

“We struck their blockers up front, knocked them back and got penetration in the backfield early,” senior defensive lineman Isaiah Buggs said. “That’s where the ballgames are won at, in the trenches.”

Buggs’ 7.5 sacks entering the game were one behind the FBS lead. By game’s end he had increased his total to 8.5 to continue a torrid pace, especially for a defensive lineman.

Junior defensive lineman Raekwon Davis did not start the game as a punishment for punching a Missouri player last week.

Sophomore LaBryan Ray took Davis’ place in the first half, making his first college start. He finished with five total tackles, three of which were solo and one of which was for loss.

“It was his first real college start and I think he did great,” Buggs said. “We always coach the young guys up to be prepared because you never know when it’s your time. Tonight was his time and he stepped up and he did a great job.”

After eight consecutive weeks, the Crimson Tide will have a bye this week, giving it extra time to prepare to play No. 5 LSU in Baton Rouge on Nov. 3.

“We’re going to be in more challenging games,” Saban said. “We’ve been 8-0 at this point quite a few times, but it’s all about how you finish. This bye week is a good time for us to try to improve so we have a better chance to finish like we want to finish and face the challenges that we have coming up in the future.”