The Cowboys closed out the game with two interceptions, as Daytawion Lowe and Zack Craig picked passes in the final minutes.
And after some shaky performances earlier this season, including defensive duds in losses to Arizona and Texas, OSU's D is finally playing like the unit propped up as a difference-maker in the preseason.
For the first time in the Big 12 era and the first time overall since 1986, the Cowboys have held three straight conference opponents to less than 20 points.
“We're healthy now,” Gundy said. “We've got some guys back. We were beat up early in the season at key spots.”
Now the Cowboys are doing the beating up – just in time for next week's visit to No. 3 Kansas State.
OSU shut out the Cyclones on their final 11 possessions and blanked the Frogs on their final 10. After a decent start, TCU managed just 223 yards over the final three quarters. And for the game, the Frogs converted just 2 of 14 third downs.
“Early in the season, we gave up some big plays,” said linebacker Alex Elkins. “And it's not that we had a bad defense, we just didn't have all 11 players hitting on all cylinders.
“We knew we had to come out here and change that. And everything we've done up to this point is worth it.”