Updated

Matthew Tucker scored two touchdowns, Jaden Oberkrom kicked two field goals and TCU's defense forced four turnovers in dumping No. 18 Texas 20-13 Thursday night to get the Horned Frogs their biggest win of their first season in the Big 12.

Tucker scored on runs of 1 and 2 yards and the Horned Frogs (7-4, 4-4) dominated the line of scrimmage, running the ball 48 times and passing just 10. TCU had two interceptions inside their own 10 to kill Texas drives and picked up a fumble by Longhorns quarterback David Ash to set up Tucker's second touchdown.

Ash was relieved by Case McCoy, who led a late touchdown drive before an interception by Sam Carter in the final two minutes sealed the win for the Horned Frogs.

Although Texas (8-3, 5-3) has been a Thanksgiving regular since playing its first game on the holiday in 1895, those contests were usually against Texas A&M. But that rivalry broke apart when the Aggies left the Big 12 for the Southeastern Conference.

So the Big 12 sent TCU to Austin this year and the Horned Frogs pushed around the Longhorns at the line of scrimmage and harassed Ash into one of the worst games of his career.

McCoy led an 82-yard drive to a touchdown by Jeremy Hills that pulled Texas within a touchdown with just over three minutes left. But after Texas forced the Horned Frogs to punt, a scrambling McCoy threw up a pass into coverage that was easily picked off by Carter.

TCU rushed for 217 yards, with a team-high 77 from freshman quarterback Trevone Boykin, as the Horned Frogs got their first win over a ranked opponent this season. TCU linebacker Kenny Cain had 14 tackles.

The Horned Frogs have had to slug their way through their first Big 12 season. They were 4-0 before starting quarterback Casey Pachall was arrested on suspicion of driving while intoxicated, got suspended and then left school for treatment at an inpatient rehabilitation facility.

TCU turned to Boykin and the freshman was coolly effective against the Longhorns, scrambling for big yards on broken plays and called runs after ball fakes. TCU's first scoring drive started with Boykin throwing out of his own end zone to direct a 94-yard march to Tucker's first touchdown.

Tucker was originally ruled down on the 1 but the call was overturned on review to give the Horned Frogs the 7-0 lead.

Ash committed two turnovers in the second quarter, throwing an interception on the TCU goal line and coughing up a fumble at the Texas 16 when the ball simply slipped out of his hand as he pulled back to throw. The fumble set up a Tucker's second touchdown, a 1-yard run that put the Horned Frogs ahead 14-3.

At that point, Texas briefly pulled Ash for McCoy, who had rallied Texas to a road win at Kansas. But McCoy couldn't move the Longhorns late in the half and Ash started the third quarter.

Oaberkrom, who missed an early 33-yard attempt, kicked field goals of 18 and 41 yards in the second half to push TCU's lead to 20-6.