Sam Houston (10-8, 5-2) rallied from six points down with 10:16 to play to tie the game 53-53 with 2:56 to play and outscore the Roadrunners 14-2 in the final two-and-a-half minutes.
UTSA (7-12, 3-3) was led by Kamra King with 13 points. The Roadrunners had more success at the free throw line than from the field as UTSA was 24-of-30 from the charity stripe (80 percent) and only 14-of-53 from the field (26.4 percent).
Sam Houston out-rebounded UTSA 46-43 and outscored the Roadrunners in the paint 24-16.
UTSA did not score its first field goal until the 10th minute of the contest on a layup by Judy Jones. But the Roadrunners, down by 10 13-3 early, roared back to take a 24-23 lead at intermission.
The victory marked only the second time this season that the Bearkats have trailed at halftime and come back to win the contest.
The Bearkats, who hit 20-of-59 from the field (33.9 percent) and 20-of-31 from the line (64.5 percent), also received nine points apiece by Jasmine Johnson and Jasmin Wiley.
Khamra Echols started the Kats' 14-2 run in the final 2:39 with a three-pointer.