The Longhorns' defense was outstanding, holding an Iowa State offense that had scored at least 41 points in each of its first three games to one touchdown and just 10 yards rushing in 15 carries.
Texas (2-2, 1-0 Big 12) ran off the final 7:35 of the clock with 13 runs, never giving Iowa State any chance to make a comeback. The Longhorns finished with a 312-256 advantage in total offense.
Iowa State quarterback Jacob Park completed 24 of 48 passes for 246 yards and a touchdown, but he also threw three interceptions.
Chris Warren III (44 yards on 16 carries) ran 11 yards for a touchdown on the Longhorns' opening possession, which was extended by a personal-foul penalty on Iowa State after the Cyclones had stopped Texas short on third down deep in its own territory.
Buechele stood tall in the pocket despite pressure from the Iowa State defense and passed 22 yards for a touchdown to freshman running back Toneil Carter midway through the second quarter to expand the Longhorns' lead to 14-0.
Texas outgained Iowa State 186-127 in the first half, with a 78-24 edge in rushing. Two Cyclones drives were squashed by interceptions of poorly thrown passes from Park by the Longhorns' Elliott and Kris Boyd, respectively.
The Cyclones (2-2, 0-1 in Big 12 play) got back in the game on a Park pass to Matthew Eaton for an 11-yard touchdown with 2:05 to play in the third quarter that cut the Texas lead to 14-7.
The Longhorns then got the benefit of two calls on potential turnovers that overturned a fumbled kickoff and a pass that was originally ruled a lateral.
Joshua Rowland line-drived a 49-yard field goal with 13:25 to play that pushed the Texas lead to 17-7 and gave the Longhorns a little breathing room.