Brian Davis added 10 points for the Aggies, who move on to face third-seeded Kansas State in the quarterfinals on Friday.
Craig Brackens led Iowa State (14-18) with 20 points and 12 rebounds, and Bryan Peterson added 14 points. They just didn't get enough help, with the rest of the team combining for 13 points on 4-of-34 shooting.
The Aggies had to have this win.
The Big 12, with its No. 3 RPI rating, could get as many as six teams into the NCAA tournament. Of those teams, Texas A&M seemed to be the most in need of extra wins in the Big 12 tournament.
The Aggies seemed to be a lock for their third straight NCAA tournament appearance midway through the conference schedule, then lost five of their final seven games, capping the season with a disheartening 72-55 home loss to Kansas.
Texas A&M played like it needed a win -- at least on defense.
Iowa State missed 14 straight shots midway through the first half, then missed seven more at the end, finally getting a shot to fall when Brackens hit a 3-pointer at the buzzer. The Cyclones shot 7-for-33 in the half, managing just 17 points.
Texas A&M's defense had something to do with it.
The Aggies have their biggest team in school history, with six players at least 6-foot-9, and they gave Iowa State all kinds of trouble inside, even with 7-foot freshman DeAndre Jordan out sick. But the Cyclones added to it, too, blowing lay-ups and tossing up airballs from 3-point range.
Scoring futility is nothing new to Iowa State this season.
The Cyclones scored 15 points in the first half against Colorado on Jan. 29 and had 11 against Nebraska on Feb. 16.
The thing is, Iowa State won both of those games. The Cyclones never put together a rally this time.
Texas A&M made enough mistakes to let Iowa State hang around for a while, with nine turnovers in the first 11 minutes and a couple of rough shooting stretches late in the first half and early in the second.
Iowa State cut the lead to 40-36 on Wesley Johnson's three-point play with 81/2 minutes left, but the Aggies slowly pulled away from there, making enough free throws in the closing seconds to finish it off.