There was little between the sides in the first half, but Rangers grabbed a goal at a crucial stage two minutes from the break. A high speed move down the right ended with Stephen Grindlay pulling off a superb one-handed save from Sean Paliczka. Steven Noble took the corner on the right that went past every defender, and Jordan Smith shot home at the far post.
Four minutes after the re-start Rangers added a thrilling second goal. They had already made four rapid passes from their own half before Ryan McCallum split open the defence. Steven Noble crossed from the left to find Robbie Manson, and his header was met by Paliczka who left Grindlay helpless.
Ten minutes from half- time Stuart Fraser headed cleverly past Grindlay after another Noble corner found him perfectly placed.
Disappointing Dumbarton managed just one shot on goal, but Gary O'Connor made a fine two-handed save from Noble.
Rangers almost added a fourth, but Grindlay was out of his goal quickly to foil Ryan McCallum who had broken clear.
The Berwick defence looked very solid with immense displays by Robbie Horn and Smith. But the whole side is developing very quickly, and with six seniors waiting to come back from injury, the future is beginning to look encouraging.