The Jayhawks held Southeast Missouri to 17 first-half points, a defensive showing which helped Kansas overcome a sub-par shooting night.
Perry Ellis added 15 points for the Jayhawks, who reached the national championship game last season before falling to Kentucky.
Kansas hit only 38 percent of its field goal attempts and made a mere 2-of-21 from 3-point range.
Southeast Missouri got 14 points from Nick Niemczyk and 12 from Nino Johnson.
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