As Welsh Cup second round seeds, Barry travelled to South Wales Alliance Premier side, Aber Valley, near Caerphilly.
Barry started brightly, and twice had the ball in the back of the net through Drew Fahiya, but ruled out through offside.
Sam Johnson scored for Barry in the 18th minute, and Barry took a 2-0 lead into the half-time break when Jordan Cotterill scored in the 44th minute.
Set up by Sam Johnson, Kayne McLaggon secured the victory by making it 3-0 in the 49th minute.
In the end, pressure from the home side earned a consolation goal from the penalty spot, Scott Armitage giving the 900-strong crowd something to cheer.
However, it was Barry who were comfortably through to the third round of the Welsh Cup, avoiding defeat away from home against the tier four opposition.