Oklahoma's defense was shaky at best and helpless at worst in OU's 48-45 loss to Texas at the Cotton Bowl on Saturday.

The Sooners defense yielded 501 yards of total offense to the Longhorns for only the second time in series history. Texas averaged a staggering 8.9 yards per play in the first half, eventually building a 21-point fourth-quarter lead.

Kyler Murray's playmaking closed the deficit in the game's final minutes, but one final Texas drive -- and a 40-yard field goal that left just nine seconds on the clock -- was good enough to secure the win.

Defensive coordinator Mike Stoops took responsibility for the shortcomings.

"I'm extremely disappointed in my inability to get this team to play at a higher level," Stoops said. "It takes everybody pulling the same way, and I certainly take a lot of that responsibility."

Sophomore quarterback Sam Ehlinger is mostly responsible for giving Stoops those feelings. Ehlinger was dominant in his second trip to the Cotton Bowl. He completed 24 of 35 passes for 314 yards, scoring five total touchdowns (three on the ground).

Ehlinger's two most damaging plays came when the Longhorns were on their heels. Oklahoma coach Lincoln Riley singled out a pair of third-and-long conversions that shook the Sooners' defense.

With the game knotted at 10, Ehlinger faced third-and-20. He hit Andrew Beck over the middle for an 18-yard gain. Texas went for it, converted, and scored on a wheel route on the following play.

Next, with Texas up 24-17, Ehlinger faced third-and-21. He hit Lil'Jordan Humphrey on a tunnel screen. The 6-4 Humphrey pushed the pile ahead, eventually stopping two yards short. Texas went for it again, converted, and scored four plays later.

"That really hurt us," cornerback Tre Brown said. "We had them third-and-long, whatever you want to say, we had a chance to get a stop and we didn't get that done. That really threw our momentum off and hurt us. And they were able to capitalize off of that."

Aside from the momentum-shifting third-down disasters, Oklahoma's secondary was historically bad. Texas' 48 points are the most it has scored vs the Sooners. Of Ehlinger's 35 attempts, only one pass was broken up by an OU defender.

"The easy throws were problematic for me," Stoops said. "All the slants we gave up in critical situations. We couldn't make a play. It's tough."

Still, OU's three defensive stops in the final stanza were impressive. Two three-and-out plays and a harmless six-play drive gave Murray a shot at history.

But one final drive from Ehlinger and the Longhorns sunk those hopes. Instead of a legendary comeback, it was an iconic kick from freshman Cameron Dicker that closed it out. OU's defense stepped up, but it was ultimately too little, too late.

"We had a surge there at the end," Riley said of his defense. "We played extremely well, more competitive, more like we expect to play near the end. But obviously we gave up too many [points]. And that's something we've all go to do a better job with."

Twitter: @Davis_Spenser

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