The loss drops the Islanders to 1-4 on the season, while UTSA moves to 4-1.
"The momentum is spinning away from us right now," said Islander head coach Scott Malone. "We have to get it going in the right direction."
The Roadrunners struck first with a single run in the first. With one away, Ryan Rummel singled and stole second. He scored from second on a single up the middle by Aaron Powell.
The Islanders had opportunities in the first and second to put some runs on the board but UTSA freshman Marc Gomez kept them scoreless.
In the first, Gomez loaded the bases by hitting three Islander batters Chris Famiglietti, Stephen Flora, and Martin Parra. Gomez, however, induced Islander slugger Trey Hernandez into an inning-ending double play. Jacob Perales and Jeremy Narvaez led off the second with a walk and a single, respectively, but were left stranded.
A&M-Corpus Christi broke through for three runs in the bottom of the third off Gomez. Brycen Bell singled to start the inning and advanced to third on a double by Stephen Flora. Martin Parra drove in both with his third triple of the young season. Parra scampered home on a grounder by Trey Hernandez to short.
The score would remain 3-1 until UTSA's offense began to warm up starting in the sixth inning and finished with 10 runs on 17 hits. The Roadrunners would take control of the game with a pair of runs in each the sixth, seventh, and ninth innings with three in the eighth.
Rockett began the scoring with a solo home run in the sixth to start the inning with Jose Hernandez crossing the plate later on a Trey Hernandez throwing error. After Tyler Carpenter and Rummel crossed the plate in the seventh to give the Roadrunners the lead, UTSA tacked three runs in the eighth as Marshal Davis tripled and Rummel doubled. Jose Hernandez ended the scoring with a two-run home run in the ninth.
A&M-Corpus Christi manufactured a run in the bottom of the ninth for the final margin as Justin Greiner scored on a passed ball.
Roy Ferdin allowed three runs on eight hits over 5-1/3 innings. Ferdin struck out four in his second start of the season, but received little help from the bullpen. After Weston Montgomery and Jake Liedka each allowed no runs in a third of an inning, Brett Carnline entered and allowed two runs in the sixth on two hits for his second loss and Brett Gibson gave up two more in a third of an inning. Jesse Maldonado and Bryant Sparkman allowed the final two runs.
"Roy Ferdin went out and held them down early on," said Malone. "(The bullpen) needs to go out on the mound and start hanging zeroes. We need to do a better job of getting the ball down in the strike zone and commanding our pitches.
"We didn't match them in pitching tonight."
Gomez tossed four innings for the visitors allowing three runs on four hits, walking one and striking out four. He hit four batters before handing the game over to his bullpen that went 4-1/3 innings before allowing an unearned run in the bottom of the ninth. Clay Schrader earned the win as he scattered two hits over four innings and fanned six. J.P. Holton struck out two.
The Islanders finished with eight hits. Narvaez and Bell each had two base hits. Lance Brown led UTSA with four hits, while Rummel added three. Four others finished with a pair.
The Islanders open Southland Conference play at Whataburger Field this weekend with a three-game set with Texas State. The first game is Friday at 6 p.m.