The Roadrunners (3-1) had six different players earn victories in singles play during the two matches, including Martin Ayala, Tyler Brown, David Kelleher and Kolby Kilgo, all of whom picked up a pair of wins on the day.
Meanwhile, the duo of Ayala and Diogo Casa finished the doubleheader with two more wins to improve to a perfect 4-0 this spring.
UTSA fell behind early after the 15th-ranked Hilltoppers (0-2) won two of three doubles contests.
However, the Roadrunners rallied to win all six singles tilts in straight sets to clinch their second triumph of the season.
UTSA then won two of the three doubles matchups to take an early lead on the 18th-ranked Cardinals (2-1).
The Roadrunners carried the momentum into singles action, where they won four of the six contests.
Ayala, Kelleher and Kilgo all captured straight-sets victories, while Brown was forced to go the distance against Mario Jakovljevic.
UIW picked up wins at Nos. 2 and 5 singles, both in straight sets.
UTSA will continue its home stand on Friday when it hosts Nevada (3-3) at 2:30 p.m.
UTSA 6, #15 St. Edward's 1
1. Ayala/Casa (UTSA) def. Agoglia/Rogers (SEU) 8-7 (7-4)
2. Bronstrup/Bake (SEU) def. Brown/Kelleher (UTSA) 8-5
3. Stockdale/Bueno (SEU) def. Kilgo/Guanais (UTSA) 8-3
1. Martin Ayala (UTSA) def. James Rogers (SEU) 6-2, 6-1
2. Diogo Casa (UTSA) def. Pedro Bronstrup (SEU) 6-2, 7-6 (7-2)
3. Tyler Brown (UTSA) def. Maximno Agoglia (SEU) 7-5, 6-2
4. David Kelleher (UTSA) def. Felix Bake (SEU) 7-5, 6-2
5. Kolby Kilgo (UTSA) def. Jonathan Stockdale (SEU) 6-3, 7-5
6. Oliver Breininger (UTSA) def. Adrian Garza (SEU) 6-3, 6-4
UTSA 5, #18 Incarnate Word 2
1. Ayala/Casa (UTSA) def. Ivic/Assuncao (UIW) 8-3
2. Brown/Kilgo (UTSA) def. DeLeon/Jakovljevic (UIW) 8-5
3. Brown/Trautmann (UIW) def. Buchalter/Guanais (UTSA) 8-4
1. Martin Ayala (UTSA) def. Leonard Ivic (UIW) 6-2, 7-5
2. Jair Assuncao (UIW) def. Diogo Casa (UTSA) 6-4, 6-4
3. Tyler Brown (UTSA) def. Mario Jakovljevic (UIW) 6-7 (5-7), 7-6 (8-6), 1-0 (10-7)
4. David Kelleher (UTSA) def. Tucker Brown (UIW) 6-3, 6-3
5. Brandon Davis (UIW) def. Eric Buchalter (UTSA) 6-3, 6-3
6. Kolby Kilgo (UTSA) def. Luke Trautmann (UIW) 6-4, 6-4