Armenteros hit a two-run homer in the eighth inning to give the RockHounds a 3-2 lead. Muncy added a three-run shot in the ninth to extend the advantage.
San Antonio starting pitcher Gabe Mosser threw five shutout innings, allowing four hits and one walk with four strikeouts.
The Missions took the lead by scoring two runs with two outs in the bottom of the fifth. Juan Zabala’s ground ball turned into a Midland error that allowed Michael De La Cruz to score. Ripken Reyes singled to drive in Korry Howell and make it 2-0.
