McDermott made three free throws after a pair of technical fouls were called on the Cornhuskers with 9:14 left. Nebraska's Toney McCray was called for a technical foul after he fouled Creighton's Grant Gibbs.
Angered by the technical on McCray, Nebraska coach Doc Sadler moved down the sideline and sat on the scorer's table and received another technical.
McDermott made three of the four technical free throws and Gibbs hit both of his free throws to put Creighton up 51-45. McDermott followed with a three-point play that put the Bluejays (7-0) up by nine.
Nebraska (4-3) never got closer than seven after that.
Antoine Young had 14 points for Creighton and Gibbs finished with 11.