And another goal three minutes later from Neil Thomas sent the Steelmen leapfrogging their opponents into fourth place in the table.
The two goals lit-up an otherwise drab affair in front of live S4C cameras at the GenQuip Stadium.
After Drew Fahiya had been brought down after a mazy run on 40 minutes, Barrow stepped-up to send a rising free-kick into the top corner.
And Fahiya's hold-up play on the edge of the box was followed by a lay-off to Thomas, who hammered the second from 18 yards beyond the grasp of Wyn Walters.
The Eagles rarely threatened, their best effort a stinging Richard Ingram shot which was well parried by home keeper Lee Kendall.
Bangor City took the spoils in the Gwynedd derby at Farrar Road, but it took a last-minute goal from Jamie Reed, his second of the game, to ensure Porthmadog left empty-handed.
Reed had earlier opened City's account in the 25th-minute and the 2-0 win saw them climb to eighth place in the table.