Arbroath stumbled to their first defeat in six games against a hard-working Berwick side.
The Borderers opened their account on five minutes when Gary Wood headed home a Marc Anthony corner kick.
They tied up the spoils four minutes from time with a delightful lob from substitute Craig Findlay.
Home side Arbroath had an even share of possession; but their crude long-ball tactics failed to trouble a strict Berwick defence.
The closest they came was when a John Cusick header was brilliantly tipped over the cross bar by visitors' keeper Gary O'Connor with 10 minutes remaining.