"That's a great team," Iowa State coach Fred Hoiberg said. "It's a great win for us for the fact that it gives us confidence that we can compete with anybody in the nation. It was good to finally get one of these at the end after struggling to close out games against Kansas here these past few years.
"I thought offensively we were really good all night with spacing. We played a lot of two-man games and we were able to knock down shots. It was just a great win for our guys. I'm really proud of them, big opportunity in front of us tomorrow."
The Cyclones (25-7) used a strong inside game in the second half to put away the Jayhawks, who were playing without injured center Joel Embiid for the fourth straight game.
"(Embiid is) a very good shot blocker," said forward George Niang, who led the Cyclones with 25 points. "He's a rim protector for them, and it's unfortunate they didn't have him. But don't take anything away from this Kansas team. They're extremely talented. They have a bunch of guys they can go to. So it was a little bit easier getting to the rim, but they're still a very talented team."
Kansas gave up the most points it has allowed all season.
"You score 83 points, you're supposed to win," Kansas coach Bill Self said. "It wasn't anything offensively. It was all on the other end. They were terrific offensively. We never got in any rhythm defensively at all.
"It's hard, when you're guarding five guys that can all shoot 3s out there all the time."
The Cyclones, the league's highest-scoring team, pulled away early in the second half and then maintained a comfortable lead. All five Cyclones starters scored in double figures, including guard DeAndre Kane with 20 and forward Melvin Ejim with 19.
Iowa State hopes to continue an unusual tournament streak. In the first 17 years of the Big 12 tournament, no team from Texas ever won, even though the state had a third of the members for the first 15 years and has 40 percent of the members for the past two years.
Iowa State won the title in its only other appearance in the tournament final in 2000.
"I definitely could tell they clogged the lane a lot more," Ellis said. "We definitely had to drive more. That was the key thing. They definitely spaced the floor well, but I felt like it's on us to have the energy and the mindset. And Coach always tells us to have the pride to defend that."
Iowa State opened the second half with a strong run, just as it did in the first half. The Cyclones connected on three 3-point shots on the way to a 20-9 start in the half. Kane had eight points in the run.
Kansas could get no closer than six points the rest of the way.
The first half settled very little, with the Jayhawks holding a 48-46 lead at the break. Iowa State got off to a hot start, racing out to an 18-9 lead before the second media timeout. The Cyclones hit four 3-point baskets in the first eight minutes, with Kane connecting twice.
But Kansas stormed back with a 16-0 run to turn a seven-point deficit into a nine-point lead.
"Coach preaches how you're going to act when adversity hits you." Niang said. "Are you going to give up? Are you going to point the finger? Are you going to point the finger at yourself? How are you going to act? He asks us that question all the time, and I feel like we came here for a reason. We didn't want to go down with a fight, so we just kept fighting, clawing, pulling, and we eventually got it on the two, even though I missed a bunny out there to tie it."
Iowa State retook the lead with a 17-6 run of its own. The teams traded buckets down the stretch. Niang's reverse lay-up at the buzzer rolled off to avoid a tie score. Ellis led all scorers with 21 first-half points.