Behanan reached his career best in the first half with 13, outrebounding the Bulldogs (12) by himself.
Gorgui Dieng had 10 points and 13 rebounds while Wayne Blackshear added 13 points with five rebounds as the Cardinals (2-0) won the opener of the Battle 4 Atlantis tournament that continues next week in the Bahamas.
Louisville never trailed in its first meeting against Samford (1-2), which was playing its highest ranked opponent since losing 79-54 to No. 1 and defending champion Florida in 2006.
Tim Williams' 15 points and six rebounds led Samford. Raijon Kelly added 11 for the Bulldogs, who committed 21 turnovers.