Kerwin Roach II added 12, though his primary assignment was slowing down the Sooners' Trae Young.
Young finished with 26 points and seven assists but struggled again from the floor as Oklahoma lost for the fifth consecutive time.
Oklahoma's freshman duo of Young and Brady Manek have carried the Sooners through much of the season, but both continued their recent struggles Saturday.
Young was just 7 of 21 from the floor and made just 3 of 10 from behind the 3-point line.
Manek came into the game shooting better than 60 percent at home but was just 3 of 13 from the floor and 1 of 7 from behind the arc.
The loss dropped the Sooners to 16-10 overall and 6-8 in Big 12 play. It was also the Sooners' second consecutive loss at home after their previous 14 home games.
The win snapped a three-game losing streak for Texas (16-11, 6-8).
Matt Coleman added 11 for the Longhorns and Mohamed Bamba had 18 rebounds as the Longhorns outrebounded the Sooners 43-31.
Christian James was the only other Oklahoma player in double figures with 11 points.
Texas led the entire way but its lead had dwindled to one after Young's 3-pointer with just more than 13 minutes to play.
Young had missed his first four 3-point tries of the game and his last 20 dating back to the first half of the loss at Iowa State a week earlier.
But Texas seized the momentum after that, scoring 12 consecutive points over the next four-plus minutes to stretch its lead to 13.
The Sooners got within seven on a couple of occasions but couldn't pull any closer.
Texas shot 54.5 percent from the floor (30 of 55) and was even better in the second half, shooting 63 percent.
Oklahoma shot just 30.8 percent from the field and 26.7 percent from behind the 3-point line, making just 4 of 15 from behind the arc in the second half.
--Field Level Media
Texas | Oklahoma | |
Dylan Osetkowski 21 | Scoring | Trae Young 26 |
Matt Coleman 5 | Assists | Trae Young 7 |
Mohamed Bamba 18 | Rebounds | Jamuni McNeace 8 |
Mohamed Bamba 4 | Free Throws Made | Trae Young 9 |
Jacob Young 2 | Steals | Kristian Doolittle 3 |
Mohamed Bamba 4 | Blocks | Jamuni McNeace 1 |