Langholm made a bad start to their league campaign when they leaked nine tries to Dunbar at Milntown.
The visitors completely dominated the early stages, taking the score to 0-25 at the break.
The interval team talk by coach Ally Little seemed to rally the Milntown men, but Dunbar got in another two tries before the hosts got off the mark, Niall Cubbon sending skipper Alasdair Cavers over.
Dunbar scored again before Steven Nicol touched down from a quick tap, with Cubbon adding the extras. The visitors ran in a ninth try on the final whistle.