NORMAN — Oklahoma's defense tried its best to carry the weight of Saturday's SEC opener.

But, to say the least, the offense didn’t hold up its end of the deal against Tennessee.

The Sooners fell to the No. 6-ranked Vols, 25-15, at Owen Field, dropping their first game of the season. It was an impressive effort for the defense, but the offense looked anemic for most of the game.

Here’s a few quick takeaways from the game:

If nothing else, this should be the takeaway from the game: The Sooners' defense is legitimate.

There was pressure for OU’s defense to perform against a high-powered Tennessee offense, and they delivered. The Vols, which averaged nearly 640 total yards a game through the first three weeks, finished with just 345 total yards while averaging only 4.7 yards per play. The running game had been their engine all season, but the Sooners limited them to just 151 yards on 2.9 yards per carry.

The defense got things started early, forcing back-to-back three-and-outs to start the game. They force fed OU’s offense early in the second quarter after Robert Spears-Jennings came on an outside blitz and stripped Nico lamaleava, which was recovered by Ethan Downs at the five-yard line. But, as the Sooners’ offense did often in the first half, they lost a fumble on the next play — which was particularly harmful considering OU trailed just 10-7.

Later in the second quarter, Trace Ford — who had his best game as a Sooner — again stripped lamaleava and it was recovered by Gracen Halton, marking their 12th takeaway of the season. But the OU offense again lost a fumble on the next play.

Even as Tennessee dominated the time of possession (35:41 to 24:28), the Sooners’ defense never really wavered. The Vols had just 141 total yards and six points after halftime. The pass rush was incredibly effective, forcing three sacks, nine tackles for loss and a quarterback hurry. Ford led the team with one sack and two tackles for loss.

That defensive effort kept OU afloat. But with the offense on life support, it just wasn’t enough.

The first half was basically a nightmare for Arnold.

The true sophomore completed just 7 of 16 passes for 54 yards in the first half, as the OU offense scored on its nine drives with Arnold in the game. But it wasn’t just the lack of efficiency, it was the glaring turnover issues. He was responsible for all three of OU’s giveaways. The first one came when he tried to throw a deep pass late to JJ Hester but underthrew him significantly. The second one came after Downs’ fumble recovery, when he fumbled the ball at Tennessee’s five-yard line.

The third turnover came after Halton’s fumble recovery. Facing pressure, Arnold attempted to throw it across the field to Zion Ragins but the ball traveled backwards and short, bouncing around before it was eventually recovered by Tennessee.

That turnover is when Brent Venables pulled the plug on Arnold, benching him in favor of Michael Hawkins. In the first half, the Sooners had just 82 total yards and averaged 2.3 yards per play. The Sooners had -20 yards in the second quarter.

Hawkins went into the game at 1:$0 mark but there wasn't immediate success. OU went three and out in Hawkins' first series, heading into halftime trailing 19-3.

The true freshman remained the quarterback after halftime, and it took him awhile to get going. The offense gained just 31 yards on the first three series after halftime. But Hawkins showed why he was a highly-touted recruit on the first drive of the fourth quarter, leading the Sooners on a 10-play, 68-yard scoring drive. He set up the drive with a 11-yard run to the goal line then capped it off with a two-yard touchdown pass to Jovantae Barnes.

Hawkins showed off his mobility and his arm on the final drive of the game. He found Jaquaize Pettaway for a 46-yard completion — the only OU play that went longer than 19 yards — and appeared to score on a two-yard run before he was ruled short. Jovantae Barnes scored from one-yard out with 1:09 left to cut Tennessee’s lead to 25-15, but the offense was stopped on the ensuing two-point conversion that effectively ended the game.

It wasn’t all positive for Hawkins, but proved to be an effective option at quarterback. He completed 11 of 18 passes for 132 yards and added 22 yards on the ground, finishing with two touchdowns. The Sooners finished with 140 total yards with Hawkins while averaging 4.0 yards per play — certainly not impressive numbers, but a massive step forward compared to the first half.

It's very likely Hawkins showed enough to earn himself the starting job moving forward.

— Kendel Dolby was injured in the second quarter and left the game on a cart. It was a devastating injury — the team gathered for a prayer then helped send Dolby off the field as he was loaded onto the cart.

Dolby had three tackles before leaving the game.

— Multiple Sooners on both sides of the ball have been in and out of the game with injuries. Nic Anderson returned and started the game, but went into the locker room late in the first quarter and returned to the sidelines without pads. Taylor Tatum also went into the locker room before halftime and never returned.

Da'Jon Terry has also been dealing with injuries in the first half.

— Branson Hickman did play. Andrel Anthony and Jake Taylor did go through warmups, but neither logged a snap.

— Gavin Sawchuk did not start at running back. On the first play, it was both Jovantae Barnes and Tatum in the backfield.

Still, the Sooners somehow only managed 36 rushing yards on 34 carries (1.1 yards per carry). Hawkins and Deion Burks (2 carries, 18 yards) led the way. The other ball carriers combined for -4 yards on 20 carries.

— The Sooners converted just 3 of 15 third-down attempts. Tennessee went 6 of 19.