FORT WORTH, Texas — Paul Dawson returned an interception 41 yards for a touchdown, TCU made a huge fourth-and-1 stop with just over 3 minutes left and the No. 25 Horned Frogs remained undefeated with a 37-33 victory over No. 4 Oklahoma on Saturday.

Oklahoma (4-1, 1-1 Big 12) had the ball after the teams had three turnovers in a span of four plays — another interception by Trevor Knight between two fumbles by TCU.

On fourth down from the TCU 22, Samaje Perine was stuffed by linebacker Marcus Mallet for no gain. Officials confirmed on a replay review that Perine, who had three TD runs in the game, was stopped short of a first down.

Dawson’s big pick for TCU (4-0, 1-0) came with 14:12 left. He reached up with both hands to grab the ball and raced untouched to make it 37-31. The Sooners got two points when Jordan Phillips blocked the extra point and Zack Sanchez returned it to the end zone.

TCU improved to 4-0 for the fifth time in the last seven seasons under coach Gary Patterson.

Trevone Boykin, the dual-threat quarterback flourishing in TCU’s new offense, was 20-of-38 passing for 318 yards with two touchdowns, and added 77 yards on 22 carries.

Boykin fumbled on a keeper in the fourth quarter, but two plays later Chris Hackett had an interception for TCU before B.J. Catalon gave it right back on a fumble at the Frogs 46 with 6 minutes left.

The Sooners picked up one first down, on Perine’s 6-yard run on third-and-1, then he had a 4-yard gain before Knight had 5 yards on two more carries to set up that fourth-and-1 play when Perine was stopped short. Perine finished with 25 carries for 87 yards, after the freshman ran for 242 yards in the Sooners’ last game two weeks ago at West Virginia.

Knight, who had been 9-0 as Oklahoma’s starter, was 14-of-35 passing for 309 yards with a 75-yard TD pass to Sterling Shepard in the first quarter that tied it at 14.

after TCU jumped ahead 14-0 on its first two drives. Knight had 13 carries for 61 yards.

Shepard had seven receptions for 215 yards, including a 53-yard catch to set up Perine’s first TD run.

TCU opened with the game a nearly 5-minute drive that ended with Boykin fumbling into the end zone on a run from the 1 that tight end Cliff Murphy recovered for a touchdown. The Frogs then went 65 yards — getting help from two 15-yard penalties against cornerback Sanchez — for Catalon’s 7-yard scoring run.

Oklahoma tied it at 24 when Michael Hunnicutt kicked a 32-yard field goal to end the first half, three plays after Durron Neal made a tremendous over-the-shoulder catch with a defender draped on him along the sideline. Neal was initially ruled out of bounds, but that call was overturned on an official replay review.

Perine had a 7-yard TD on Oklahoma’s opening drive at halftime, but TCU responded with Boykin throwing a 29-yard scoring pass to Deante Gray on the next possession.