The Jayhawks' furious rally came up short, as Ali Farokhmanesh hit two free throws with four seconds left to knock the top-seeded Jayhawks out of the tournament.
The sophomore forward contributed 26 points on 12-for-15 shooting, as the Jayhawks overcame a sluggish start to put away the Mountain Hawks in the second half.
Marcus Morris scored 18 points, while Tyrel Reed added 15 as the Jayhawks defeated the Wildcats for the third time this season. Collins was named the tournament MVP.
The Jayhawks used a 16-0 second-half run to pull away, advancing to Saturday's Big 12 championship game.
Jayhawks hit 2,000-win milestone in triumph over Red Raiders.
Missouri upset by Nebraska; Texas Tech defeats CU, 82-67.
Five KU players scored in double figures as the Jayhawks closed out the regular season with a runaway victory over the Tigers.
The Jayhawks used a 27-10 spurt in the second half to send senior guard Sherron Collins to a win in his final home game.
The Cowboys made 60 percent of their field goals and 53 percent of their three-pointers to send the Jayhawks to their first Big 12 loss.
Xavier Henry led the Jayhawks with 23 points on 9-for-13 shooting.
The KU sophomore guard had 17 points on 6-for-7 shooting with six assists, helping the Jayhawks to the blowout win.
Saddled with four fouls, the Kansas sophomore made crucial plays down the stretch to help KU end the game on a 7-0 run.
Kansas held Iowa State to 34-percent shooting and used a 14-0 second-half run to pull away.
The Jayhawks held the Longhorns without a point for a 10:56 stretch in the first half, using a 22-0 run to pull away.
The Cornhuskers led by four early in the second half, but the Jayhawks followed with a 28-5 run to take control.