Oklahoma hoped days like this were in the past.

The No. 2 Sooners entered the season among the favorites to contend for the national title in part because the defense had improved significantly the past two years under coordinator Alex Grinch. What once had been one of the nation’s worst units had become an asset.

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It was more of a liability at times on Saturday. The Sooners struggled in the second half and did just enough to hold off Tulane for a 40-35 victory.

Oklahoma led 37-14 at halftime, then the offense stalled and the defense was forced to get a stop in the final minutes to preserve a season-opening win. Tulane outgained the Sooners 230 yards to 118 after the break and outscored them 21-3.

Grinch said his players didn’t heed his warning, and the result was an all-too-familiar collapse in the second half — just like the one that led to a loss to Kansas State last year.

"You explain to the guys at halftime there’s more adversity coming, and the eyes staring back at you, and then heads are shaking, heads bobbing ‘I got you Coach,’" he said. "There’s been other instances in our past where similar things have happened.

"It’s a 60-minute football game. That team across the way is going to fight tooth and nail to find a way to get points and get themselves back in the football game. You’ve got to have respect for that."

The Sooners, who led 40-22 early in the fourth quarter, gave up a pair of late touchdowns. Tulane had fourth-and-13 just short of midfield with just under two minutes to go when quarterback Michael Pratt ran for 12 yards and the Green Wave turned the ball over on downs.

"We always preach finishing in the fourth quarter," Oklahoma linebacker Nik Bonitto said. "The defense knew we needed a stop, and I feel like we did a good job rallying up before that drive happened and making sure that we could finish the game."

Grinch was proud of the Sooners for getting that stop.

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"Your logo ain’t gonna win you a game at that point," he said. "You’ve got to go make a play and find a way, and (Tulane) ended up being a yard short. As disappointed as I may sound right now, I feel a whole lot better that we made that play as opposed to not."

The Sooners often pressured Pratt, only to see him escape and turn losses into gains. He passed for 296 yards and three touchdowns and rushed for 34 yards and another score.

The Sooners sacked Pratt four times and made him fumble three times in a game that was relocated from New Orleans because of Hurricane Ida. But overall, the Sooners weren’t satisfied with their performance.

"I certainly thought we’d play a better ballgame," Grinch said. "I did. So I’m going to be awfully disappointed in that film but awfully pleased that we found a way to win."