NORMAN — R Mason Thomas picked quite a time to have his breakout moment at Oklahoma.

With the Sooners clinging to a 12-point lead midway through the fourth quarter, the defense was again called upon to make some plays. The junior defensive end responded not once, but four different times.

On first down, Thomas sacked Tulane QB Darian Mensah for a five-yard loss. On third down, Thomas deflected Mensah's pass to the ground setting up a fourth-and-13. On that fourth down, Thomas again sacked Mensah for five yards, forcing a turnover on downs. Tyler Keltner made a 39-yard field goal that pushed the lead to 34-19.

That four-play sequence, for all intents and purposes, was the R Mason Thomas drive.

"It’s a guy who is now reaping what he has been sowing," OU safety Billy Bowman said. "A guy who works every single day. He has had some injuries that I’m pretty sure has had his head down. He’s found a way to pick himself back up and continue to work. Proud of him. It showed tonight how good of a player he is."

Thomas wasn't done there. He pursued Mensah on Tulane's final drive and came away with a strip sack, effectively icing the game.

Thomas finished with three tackles for loss, a forced fumble and recovery and was responsible for all three sacks the defense recorded. All of that came in the second half. He played a career-high 50 snap against the Green Wave and finished with a Pro Football Focus performance grade of 91.3 and a pass-rush grade of 92.3, both marks the highest on the team.

"Leading up today, we had been hitting with the pass rush," Thomas said. "And you know how sacks come — you may rush the passer 40 times and only get there two times, but it's been building up from the first quarter, second quarter, third quarter. And then the fourth quarter is when it finally hit. I was sticking with the same move and if it's not broke, don't fix it.

"That's how it is most games, and you see it in the NFL a lot, too. If you just keep going and keep the same motor... eventually it's going to come."

That fourth quarter underscored just how much things are pointing up for Thomas. He dealt with injuries through his first two seasons and was limited to just 10 games and 175 snaps last year, per Pro Football Focus. But the potential was always there, and Brent Venables referred to Thomas as the team's best defensive end during fall camp last season.

But now he's fully healthy and has started the first three games for OU. He's solidified himself as a huge part of OU's defensive line and he's the latest example of a player growing in their third year.

“Honestly, man, R Mason’s a ball player," OU linebacker Kobie McKinzie said. "He’s always been that. He’s a gamer, as I like to say. And honestly, just the right moment, an opportunity came, and he seized it. I wouldn’t say that isn’t who he is, because I believe that is who he is. He’s shown that consistently, honestly.”

Thomas acknowledged his first two years were tough as he dealt with injuries, but now things are coming together.

"Especially on the recovery side, I didn't know all these remedies and the process you had in taking care of your body like that in high school," Thomas said. "I had some of it, but getting with the trainers, our recovery staff and just (improving) mentally and physically better week by week.

"I think Year 3, you kind of know where you're at."

Kendel Dolby didn't play on Saturday, with Woodi Washington and Samuel Omosigho primarily taking the cheetah reps. Venables said there was "hope" Dolby would play, but didn't specify a timeline for his return.

Venables said it was "encouraging" to see Andrel Anthony in warmups without a knee brace.

Venables said the Sooners are "hoping" that Nic Anderson and Branson Hickman return next week.

The Sooners made a couple noticeable changes to the starting lineup on defense. In addition to Washington starting for Dolby in his absence, Gracen Halton made his first career start in place of Jayden Jackson.

Another guy making his first start was Kobie McKinzie at linebacker. McKinzie finished with four tackles and a tackle for a loss. But most importantly, he was part of the play that resulted in Billy Bowman's interception. After Kani Walker made the initial pass breakup, McKinzie also got a hand on it before Bowman came down with it.

“It was an opportunity well-deserved, and at the same time I’ve never been jealous or had envy toward anyway who’s been out there before me, because if you have, you’ve earned that right," McKinzie said. "Things lined up, and the opportunity came, and I seized it, honestly. It wasn’t anything special. Obviously, I’ve done the right things to put myself in those situations, so just went out there and capitalized on it."

The Sooners, like they did against Houston, utilized a lot of two-running back sets featuring both Taylor Tatum and Jovantae Barnes. That formation played a big role in the second quarter, when Jackson Arnold faked the handoff to Barnes before finding Tatum for a nine-yard touchdown.

"I just like how unique it is," Arnold said. "I think it reminds me of OU from, what, 5-6 years ago. It brings a different dynamic to our offense. It's obviously a different picture the defense has to adjust to. I don't know how the defense treats that or has an answer for that, but it brings a different personnel grouping, obviously, a different picture and obviously mixes things up for us."

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