Iowa State gave No. 2 Houston a not-so-friendly welcome to the Big 12 on Tuesday, upsetting the Cougars 57-53 inside Hilton Coliseum and knocking off the last undefeated team in college basketball. Cyclones guard Tamin Lipsey led ISU with 14 points and the Cyclones forced Houston into an uncharacteristic 16 turnovers to bounce back from their league-opening loss to Oklahoma over the weekend.

Cyclones freshman Milan Momcilovic finished with 11 points as he continued his stellar Year 1 campaign in Ames, marking his sixth-straight double-digit scoring performance. Momcilovic had a quiet second half after helping ISU to an early edge with a team-high three made buckets in the opening frame, but he made his only field goal in the second half count in a big way, draining a clutch jumper with 31 seconds remaining to give ISU the lead for good.

Iowa State (12-3, 1-1 Big 12) threw a haymaker out of the gate by opening on a 14-0 run before Houston (14-1, 1-1) could even get on the board, putting the Cougars in position to play from behind virtually all game. Guards Jamal Shead and Emanuel Sharp turned in 34 combined points, but 17 team turnovers and a woeful 3-of-13 shooting performance from 3-point range helped ISU deliver Houston its first loss as a member of the Big 12.

Houston entered the game ranked ninth nationally in fewest turnovers committed per game but gave it away 16 times against ISU. Its 16 turnovers was the most in a game since 2022, and the swirling Cyclones defense made the Cougars pay for it, finishing with a 17-6 edge in points off of turnovers. 

Iowa State was a 3.5-point underdog to Houston entering the game but the upset should hardly come as a surprise given its success against highly-ranked teams at home. The upset gave ISU its 14th home win over a top-10 team since 2011-12, second among all Division I teams behind only Big 12 foe Kansas, which has 17. It also was its seventh win against a top-10 opponent since the start of 2022-23, which is the most in Division I.

Here are three takeaways from the game.

1. Welcome to the Big 12, Houston

Last season, Houston went 17-1 in AAC regular-season play. The year before: 15-3. The year before that: 14-3. 

Big 12 play won't come quite as easy.

Houston may very well go on to win the Big 12, to be clear -- this team is physical and disciplined and a general coach's nightmare to prepare for -- but it's a pretty sobering reminder of how different the competition will be for it in a new conference after building up to a juggernaut before departure of its old league. 

2. Iowa State's D is real, and spectacular (again)

From efficiency-adjusted metrics at both and, Houston still has the No. 1-rated defense in college basketball. But Iowa State's havoc-wreaking wrecking ball defense isn't trailing far behind. ISU's defense is up to No. 3 in adjusted efficiency ratings after forcing 16 turnovers and snatching eight steals as a team. Houston was at times flustered by ISU's physicality and pressure, which is something we say mostly about opponents of Houston -- not Houston itself. The Cyclones are second in steal rate, second in turnover rate and 15th in defending against shots inside the arc. Even when the offense is inconsistent, you can bank on that to translate to big wins. 

3. No more unbeaten teams

Houston was the only team in college hoops still unbeaten before Iowa State conjured its Hilton Magic on Tuesday, leaving us with zero undefeated teams on the season. Not only does it officially eliminate the possibility of an undefeated national champion -- which hasn't happened since Indiana in 1975-76 -- it also continues a trend of the last undefeated team going out relatively early in the season, as the NCAA's David Worlock laid out:

Last year, it was Jan. 3 when there were no unbeatens still standing. The year prior it was Jan. 11.