Bryce Douvier's last second 3-point attempt was off the mark for Texas A&M-Corpus Christi.
Holliday nailed a 3-pointer to give Lamar a 63-59 lead with 1:57 remaining. Douvier answered with a 3 and Holliday then split a pair of free throws for a 64-62 advantage with 1:04 left. Brandon Pye hit a jumper to tie but then Holliday drove in for the winning layup.
Holliday, who was 3 of 4 from long range, also had eight assists and had 17 points in the second half for Lamar (9-7, 3-1 Southland Conference).
Pye made 5 of 8 3-point attempts to total 21 points, Rashwan Thomas had 15 and Douvier added 13 for the Islanders (7-8, 2-1).