The Mavericks (14-18, 6-6 SBC) won their fifth straight Sun Belt game with a 6-1 to open the day, but lost 6-5 in 10 innings in the second game.
The Mavericks (13-17) evened their league record at 5-5 in the series opener.
UTA improved to 4-5 in league play and ran its winning streak to a season-high four straight games.
UT Arlington improved to 11-16 and 3-5 in Sun Belt Conference play going into Sunday's series finale.
UT Arlington finished off its six-game stand at Clay Gould Ballpark with a 4-2 record.