VMI would get the ball back with 4:19 remaining, with Ironside finding Aidan Twombly on third and long to keep the drive alive, ultimately leading to the score from Johnson.
Alex Oliver intercepted Luke Durkin to seal the game for VMI.
The victory gives VMI a 1-0 start on the season, and marks the first win at VMI for head coach Danny Rocco.
“It really meant a lot,” Coach Rocco said of the win. “It’s been six or seven months. We’ve put in a lot of work. And you could tell the team was making improvements.”