Jonathan Holmes scored 23 points and Cam Ridley had 16 points and 11 rebounds as Texas overpowered the struggling Cyclones 86-76 on Saturday.
It took Texas (14-4, 3-2) nearly a month to get its first Big 12 win last season, the program's first losing season in 15 years.
Javan Felix scored 17, including a big 3-pointer in the momentum-changing run in the second half and a layup in the final minute that helped the Longhorns protect their lead.
Georges Niang scored 18 to lead Iowa State(14-3, 2-3), which hadn't lost three in a row since the 2010-11 season. Melvin Ejim scored 17 for the Cyclones, who went 11 of 32 on 3-pointers.