Texas (24-8) will play second-ranked Kansas for the conference title on Sunday.
JamesOn Curry had 24 points and Mario Boggan 21 points and eight rebounds for Oklahoma State (22-12).
The Longhorns have won eight of their last nine games heading into Sunday's final with the only defeat in that stretch coming to Kansas, 90-86, March 3.
Last year, Kansas beat Texas, 80-68, in the championship game.
Celebrity Families of 2014 [PHOTOS]