Johnny Hill missed a tying 3-pointer with 33 seconds left and got himself ejected nine seconds later for a hard foul. After the two technicals were assessed, the crowd threw debris on the court, causing a third technical.
Creighton wound up making nine free throws down the stretch to pull away for an 87-78 win Friday night.
"We beat a really good basketball team tonight," Creighton coach Greg McDermott said. "We knew it was going to be tough coming in here tonight. And it was."
Hill made two big 3-pointers in the final five minutes. His second one cut Creighton's lead to 77-75 with a minute left.
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"We are in the middle of a very tough three-game stretch and, given that, I was amazed we were only down a possession with less than a minute to go."
Ethan Wragge made two 3-pointers shortly after halftime to help the Bluejays (15-2, 5-1) get out to a 64-46 lead.
Bryant Allen scored 29 points for Illinois State.
"We had no answer for Allen tonight," McDermott said. "None. He beat us off the dribble. He beat us off the screen. He's just a very good player and he showed it tonight."
Jackie Carmichael had 14 points for ISU, and Hill finished with 9.
Jahenns Maigat and Ethan Wragge scored 14 points each for Creighton and Gregory Echenique had 10 rebounds.