During a key sequence to begin the fourth quarter last weekend, Ohio State quarterback J.T. Barrett rolled right hoping to convert on fourth down in Oklahoma territory. Instead, Sooners true freshman linebacker Kenneth Murray sliced through a seam of blockers and leveled Barrett, forcing him to throw incomplete into triple coverage.
Minutes later, Baker Mayfield had Oklahoma in the end zone again. And when sophomore cornerback Parnell Motley intercepted Barrett on Ohio State's ensuing offensive play, the Sooners effectively put the Buckeyes away with another touchdown.
Mayfield, who has consumed all of the media oxygen after a brilliant performance in the 31-16 victory at Ohio State, might have planted the crimson flag at the Horseshoe. Quietly, however, it was the Oklahoma defense that staked a claim in Columbus as a unit capable of being a championship-caliber complement to its Heisman-hopeful quarterback.
"That's the story," Sooners coach Lincoln Riley said. "How well our defense played."
The story of the Big 12 in recent years has been quite the opposite. As a league believed to be heavy on quarterbacking and offense, yet too lean on tackling and defense to truly compete for a national championship, the College Football Playoff selection committee in turn has treated the Big 12 like a one-sided, second-class conference.
Saturday night, the Sooners turned that narrative on its head, while doing the same to Barrett.
"We're ready to get that stereotype out of there," said senior safety Steven Parker. "We really wanted to go out and dominate."
That's exactly what the Sooners did in handing Ohio State its worst home loss in 18 years.
And the domination started with Parker and an Oklahoma secondary that appears to be among the most improved position groups in college football.
Last year, the Sooners surrendered four receiving touchdowns alone to Ohio State's Noah Brown. This time around, a deeper, faster and more complete Oklahoma secondary gobbled up the Buckeyes' receiving corps in coverage -- a big reason why Barrett connected on only five of 14 attempts of 10 yards or more downfield, including that critical fourth-down incompletion.
"You have to have [defensive backs] in this era of football," defensive coordinator Mike Stoops said. "Last year they were able to just throw balls up and catch them.
"We contested a lot better."
One of the reasons for that has been the emergence of Motley, who has shored up Oklahoma's most glaring weakness from last year -- cornerback opposite All-Big 12 defender Jordan Thomas. Through much of a tumultuous 2016 defensively, the Sooners cycled through a series of inexperienced corners, to little avail.
After putting on the necessary weight, Motley finally got his shot during the spring. And though he was the star of Oklahoma's spring game, Motley's coming-out party truly arrived in Columbus, where he finished with eight solo tackles, a tackle for loss and the game-clinching pick, in which he baited Barrett once Murray flushed him out of the pocket.
"He made a big-time play in a big game," Thomas said of Motley's interception. "That separates you from everyone else when you can do things like that, especially as a sophomore."
"Parnell Motley was the difference," Stoops said. "They didn't throw at Jordan much. [Motley] met the challenge."
With Motley, Thomas and Parker holding firmly at the back end, Stoops was able to commit more resources to flank his three-man front at the line of scrimmage. And with athletic linebackers Obo Okoronkwo, Caleb Kelly and Murray wreaking havoc off the edge, Oklahoma mostly bottled up the Ohio State running game while keeping the heat on Barrett.
"Our secondary play is probably the biggest difference [from last year]," Riley said. "When you [cover] you can take more chances up front to try and get some more pressure.
"It's made a big difference for us so far."
So far, the difference from last season has been significant.
Beginning with that 45-24 loss to the Buckeyes, the Sooners gave up 40 or more points in four of five games, which culminated with a ridiculous 66-59 shootout victory at Texas Tech, in which Patrick Mahomes passed for 734 yards.
From that moment on, though, the Sooners gradually improved, and closed out the season by shutting down Oklahoma State and Auburn.
That gave the defense a little momentum and confidence into the offseason.
"We got so tired of people talking about us [negatively]," Parker said. "We really wanted to change that, change the culture.
"You see us now playing with a different toughness, a different edge. We're playing with speed and almost killing ourselves running to the football."
That edge has been reinforced with better recruiting.
Kelly, a native of Fresno, California, was the No. 69-overall recruit in 2016, and chose the Sooners over Michigan, Oregon, Texas and Notre Dame. He was inserted into the starting lineup midway through last season, which coincided with Oklahoma's improved play.
The Sooners have also hit home runs on Murray and Motley, whose recruiting went largely under the radar.
The combination of such young players filling in the gaps alongside Parker, Thomas and Okoronkwo, who has established himself as one of the most relentless pass-rushers in the country, has created potentially the stoutest defense the Sooners have fielded since the turn of the decade.
"We've had so many people step up with the incoming freshmen and the sophomores," Parker said. "Everything is running on all cylinders. We feel like we've found the right mix."
That mix, however, is likely to face tougher challenges ahead.
As imposing as the Sooners were defensively, Ohio State's offense has had problems for some time. After all, Barrett and the Buckeyes were shut out in the playoff by Clemson to end last season, then struggled offensively through the first half of a Week 1 win at Indiana.
The Big 12, meanwhile, remains as lethal as ever offensively, most notably at Bedlam rival Oklahoma State, which, behind quarterback Mason Rudolph and wide receiver James Washington, boasts perhaps the most dangerous offenses in college football.
"We're definitely going to see some high-powered offenses, similar to ours, that spread the ball around," Parker said. "We know we're going to have a lot on our plate.
"But if we keep on improving, we feel like we should have the best defense in the country."
That might seem like an unrealistic jump, considering Oklahoma's struggles defensively in recent years. Then again, with so many budding standouts, the Sooners' upward trend on defense figures to continue.
Parker and Thomas might be four-year stalwarts. But Okoronkwo, Kelly and defensive tackle Neville Gallimore are just second-year starters; Motley and Murray were both making just their second career starts in Columbus.
That contingent sent a message at Ohio State.
These Sooners aren't just about Mayfield. And great defense could be on the way back at Oklahoma.
"This group has a chance," Stoops said. "Our will, our ability to compete is stronger.
"That bodes well for down the road."