The Bluejays, who reached the third round of last season's NCAA Tournament, put together a 16-6 surge over the final 6:30 of the opening period to build a 14-point advantage.
McDermott contributed 19 points and 11 rebounds while Austin Chatman added 13 points. Creighton made half its field goal attempts and hit 18-of-22 from the foul line.
Tony Mitchell scored 18 points to lead North Texas, which is coming off an 18-14 season.
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