James played a team-high 36 minutes and was 11 of 17 from the field. Anthony Miles added 16 points, six rebounds and eight assists for the Cardinals (5-3), and Devon Lamb had 12 points, eight rebounds and four steals.
Raymone Andrews had 16 points, including three 3-pointers, for the Ragin’ Cajuns (4-6), and Josh Brown added 13 points and nine rebounds.
Lafayette was within two, 41-39, after an Andrews 3-pointer with 16:08 to play. Lamar responded with a 23-6 run over the next 7 1/2 minutes, capped by a Lamb layup that made it 64-45 with 8:43 left.
With the win, Lamar evened its record against Lafayette at 41-41. The schools were rivals in the Sun Belt Conference before the Cardinals left in 1998.