The Mavericks (9-10, 4-3 Sun Belt Conference) were nursing a three-point lead when a Brandon Williams dunk ignited a quick 9-4 run to close the first half and grab a 37-29 lead at the break.
South Alabama (7-13, 1-6) opened the second half on a 17-8 surge and grabbed the lead after 3-pointers by Ken Williams and Barrington Stevens.
UT-Arlington responded as Jamel Outler sank a 3-pointer to fuel a 12-3 surge and put the Mavericks up for good, 64-56 with 3:10 remaining.
The Mavericks shot 46.9 percent from the field. Lonnie McClanahan scored 19 points.