The Ragin Cajuns (9-4) pulled away early as Long had a three-point play, two 3-pointers and a jumper to spark a 17-0 run to open the game. Louisiana-Lafayette coasted to a 46-26 halftime advantage and shot 49.3 percent from the field.
Long, who averages 21.2 points a game, finished 11 of 15 from the field. Kevin Brown added nine points for the Ragin Cajuns.
Central Methodist (7-8) started the game cold as it missed its first eight field goal attempts and had five turnovers, stumbling to a 36.8 shooting percentage. Mitchell Farr ended the scoring drought with a jumper at the 14:28 mark. He had 26 points on 8-of-15 shooting and hit four 3-pointers.
Mike Krzyzewski says he has good reason to be excited for next season thanks to a combination of Duke's incoming freshmen and a core of experienced upperclassmen.
Georgia guard Juwan Parker has been awarded a medical redshirt, leaving him with two years of eligibility, after missing the 2015-16 season with a partially torn Achilles tendon.
Forward Trevon Bluiett has withdrawn from consideration from the NBA draft and will return to Xavier for his junior season.