Laylia de Crus right-footed a shot into the net on a pass from Valentia Lefart at the 44:54 mark to up the Roadrunners up 1-0 at halftime.
Edith Lopez headed in an insurance goal in the 63rd minute on a cross from Jodi Leroy.
Sam Houston falls to 4-8-1 for the season and 0-2 in Southland Conference play. UTSA Ari Calderon was credited with two saves on eight shots by Sam Houston as the Bearkats were blanked for the fifth time this year.
Hilary Ackerman and Tricia Mallory each had two shots to lead the Bearkat offense.
Mallory Garthwaite faced 11 shots from the Roadrunner attack, chalking up two saves.
Sam Houston returns home to Joseph Pritchett Field to host Northwestern State Friday at 7 p.m. The Bearkats also will play Central Arkansas next weekend in a Sunday 1 p.m. contest.