Davion Buster had 17 points for Lamar (16-12, 9-6 Southland Conference), which earned its fifth consecutive victory. Jordan Hunter added 12 points. Christian Barrett had eight rebounds for the visitors.
Emmanuel Toney had 17 points for the Islanders (11-16, 6-8). Kareem South added 15 points. Irshaad Hunte had 12 points and seven rebounds.
The Cardinals improve to 2-0 against the Islanders on the season. Lamar defeated Texas A&M-Corpus Christi 61-55 on Jan. 5. Lamar plays Houston Baptist at home on Wednesday. Texas A&M-Corpus Christi faces Abilene Christian at home on Wednesday.