NORMAN — Amidst all of the chaos for Oklahoma's offense on Saturday, there was an important clarification on the other side of the ball.

Oklahoma's defense is done rebuilding. The first major test of the season came, and the defense passed it with flying colors.

It's ready to win now.

Against an explosive Tennessee offense, the Sooners limited them to just 345 total yards — nearly 300 fewer than their per-game average coming into the contest, and forced two turnovers after Tennessee had committed just three on the season. But more importantly, the Sooners gave up just 22 offensive points to a team that averaged 63 points per game through the first three games.

With the offense simply unproductive, especially in the first half, the defense was the only reason the Sooners remained in their game

"Thought our defense played really well tonight for the most part," OU coach Brent Venables said after the game. "Would love to have caused another turnover or two, but our guys played with tremendous effort. Thought they had a great plan defensively. Our coaches, and players just played very inspired football. Proud of those guys, the toughness and the leadership that they showed. A team like Tennessee, as we know, you can’t give them easy opportunities. They forced some of those as well."

Here's how the Vols fared on offense against the Sooners compared to the first three weeks:

The defense also, notably, showed that they had some tricks up their sleeve.

The Sooners rarely ran three-man fronts on the defensive line through the non-conference schedule, but implored them regularly against Tennessee. Gracen Halton and Damonic Williams combined to line up outside the offensive tackle on 50 snaps against the Vols after doing that for just 10 snaps through the first three weeks.

The Sooners used those sets to generate a ton of pressure on Tennessee quarterback Nico lamaleava. He was sacked three times and hurried five times, and he was pressured on seven of his 27 drop backs, per Pro Football Focus. The Sooners made things tough on the young quarterback, as Trace Ford and Robert Spears-Jennings both forced strip sacks.

The Sooners recorded a pass-rush grade of 76.4 against Tennessee, per PFF, and have the third-best pass-rush grade among all FBS teams (84.9) through the first four weeks.

“We tried to hold some stuff that we hadn’t shown the first couple of games to try to throw them off a little bit on some of their reads and things they were trying to do," OU defensive coordinator Zac Alley said. "I felt especially early in the game that we did that pretty well. Couple of the issues we had were really just kind of one-on-one, winning one-on-one balls more than anything else.

"But I thought the quarterback was a little off balance and they did a good job protecting him, running the ball, trying to keep it out of his hands. I thought we had a good game plan for it.”

The run defense continued to be elite against a Tennessee team that has largely relied on its running game. With the OU offense struggling and the pass rush getting to lamaleava, the Vols slowed the game way down in the second half.

The Vols held possession for over 17 minutes in the second half and ran 34 plays. They only attempted 10 passes (five completions for 68 yards) as they looked to slow the game down, but still only averaged three yards per carry in the second half and only scored three points after halftime.

"I understand Tennessee, everything changed a little bit with what they were going to do (in the second half)," Venables said. "I also saw us play when everything was wide open, they had a wide-open playbook, and watched our guys compete and perform at a really really high level. Things were going to be difficult all night long, based on what I saw."

The Vols did break through on a couple big passing plays, as lamaleava completed four passes of 38 yards or more, including a 66-yard touchdown to end the first quarter. Venables attributed those plays to defensive backs getting beat and not coverage breaks. But given the Vols possessed the ball for over 35 minutes, a few of those plays might've been expected.

"Obviously you’d like to win every one on one that goes up," Alley said. "You know that you probably won’t throughout the year. You play good people, they’re gonna make plays just like your guys will. But obviously encouraging if we have an opportunity to limit teams to explosive plays, and even (on some of) the explosives we held them to field goals. That’s something you wanna do when you have an opportunity when you have something like that.

"Proud of our guys. I think if we eliminate a lot of those wide open big explosives throughout the year, we’ve got a chance to be really good.”

There's no doubt that the defense has made huge strives since Venables' first season. On the season, the Sooners rank tied for first nationally in takeaways (12), 11th in tackles for loss (28), seventh in sacks (14), 26th in scoring defense (14.8 points per game), 27th in rushing defense (96 yards per game) and 28th in total defense (284.8).

The Vols offense could also be the most explosive they've faced all season, and the Sooners' defense played well enough to keep them in the game.It's not going to be easy the rest of the way, by any means. They still have to play high-powered offenses like Texas, Ole Miss and Alabama, and the Sooners also lost Kendel Dolby to a dislocated ankle.

But the Sooners proved that the defense is up to the challenge. Now it's about the offense doing its part.