Decensae White added 11 for Texas Tech (20-11, 9-7 Big 12), which reached the 20-win mark for the fifth time in six seasons under coach Bob Knight. The Red Raiders also avoided a loss that would have dampened their NCAA tournament aspirations.
Jackson hit a runner to put Texas Tech up by five, 62-57, but Iowa State's Wesley Johnson answered with a quick 3 that made it 62-60 with 29 seconds left. The Cyclones then forced Texas Tech to throw the ball away, and Rahshon Clark got to the line with 11.7 seconds left.
Clark made only one of two free throws, forcing the Cyclones to put Charlie Burgess on the line. Burgess missed his second free throw, sending Mike Taylor on a mad scramble down the floor. The Cyclones never got a chance to send the game into overtime, though, as Corey McIntosh couldn't get a shot off before the final buzzer.
Jiri Hubalek led all scorers with 25 points -- one shy of his career high -- and Johnson added 16.
Taylor's 3-pointer pulled Iowa State (15-15, 6-10) within two with 2:03 left. But Jessan Gray missed a putback under the basket that would have tied the game, and Johnson front-rimmed a jumper on Iowa State's next possession.
Iowa State led by as much as seven early in the second half, but Texas Tech jumped ahead with a 14-3 run that was capped by a 3 from White. Iowa State got within 53-50 before Alan Voskuil stripped Clark and hit a layup on the other end.
Iowa State tied the game at 29 by halftime on an alley-oop layup by Johnson. Hubalek scored the Cyclones' first 13 points, but the Red Raiders held him to just two in the final 12:45 of the opening half.
Iowa State's six Big 12 wins matches their total from a year ago, despite the fact that first-year coach Greg McDermott had only four scholarship players back from 2005-06.