Texas lost three out of four late in the regular season, but the Longhorns started quickly against the Sooners and regained the form that pushed them as high as No. 2 in the national rankings this year.
Hamilton added 10 rebounds while Tristan Thompson had 13 points and 11 boards. Texas took an 11-2 lead and held a 43-20 advantage at halftime. The Longhorns had 12 offensive rebounds to just one for the Sooners.
Texas (26-6) will meet either Missouri or Texas A&M in the semifinals Friday. The other semifinal will send No. 2 Kansas against surprising Colorado. The Jayhawks fought off Oklahoma State 63-62 and Colorado put together an 87-75 upset of No. 23 Kansas State.
Oklahoma (14-18) was led by Cade Davis with 17 points.