Shelly Lancaster (6-3) spread eight hits over seven hitting, allowing the Roadrunners just one run.
The victory ups Sam Houston's season record to 8-10 while San Antonio stands 9-8 for the year.
Hillary Adams put the Kats on the board in the second inning with a solo home run to left field.
Alyssa Coggins walked in the fifth inning, moved to second on a single by Jessica Slater and scored on the hit by Damian.
The Bearkats and the Roadrunners will meet in a double header at 1 p.m. Saturday.