Eric Tate went 4-5 and drove in the go-ahead runs with a base-loaded single in the eighth inning.
UTA has won five of its last six games in Sun Belt Conference play.
UTA won its fifth straight Sun Belt game to open the day, but lost the second in extra innings.
First pitch of the series vs. ULM is scheduled for 6:30 p.m. on Friday.
UT Arlington improved to 11-16 and 3-5 in Sun Belt Conference play going into Sunday's series finale.