Releford canned five treys en route to 19 points. Johnson connected on 4-of-5 long-range shots on his way to 12.
Jeff Withey (11 points), Perry Ellis (11, 10 rebounds) and Naadir Tharpe (nine, 12 assists) also played big roles for the Jayhawks (11-1), who notched their 10th straight win.
American (4-9) was led by Stephen with 16 points.
John Schoof also reached double figures with 14 points for the Eagles.