McNeese State (11-15, 5-10 Southland) went on a 20-0 tear during five minutes early in the second half to break away from Central Arkansas (1-24, 1-13), which lost its fifth straight.
Garrett chipped in a jumper and a layup during the run. Kevin Hardy added 16 points and four blocked shots, Desharick Guidry added 13 points with 11 rebounds and Jamaya Burr 12 points with nine assists for the Cowboys.
Mathieu Kamba led the Bears with 14 points and Jordan Howard added 13.
McNeese State shot 52.5 percent (32 of 61) from the field, with 12 steals and nine blocks. Central Arkansas finished at 41 percent shooting from the field (24 of 59) with 18 turnovers, which led to 31 points for McNeese State.