Chris Washburn and Kyan Anderson scored 16 points apiece, and TCU held on down the stretch to beat Kansas State 67-65 on Wednesday night for its first Big 12 tournament victory.
Trey Zeigler added 15 points for the ninth-seeded Horned Frogs (18-14), who had been one-and-done in their first two trips to the Sprint Center.
TCU will play No. 1 seed Kansas in the quarterfinal on Thursday afternoon.
Thomas Gipson had 16 points and Nino Williams finished with 13 for the No. 8 seed Wildcats (15-17), who finished the season with a losing record for the first time since 2003.
The latest news from around North Texas.
TCU had built a 58-46 lead with 6 1/2 minutes left, but the Wildcats managed to trim it to 64-62 when Williams converted a three-point play with about a minute to go.