Giuliano Grazioli's 17th goal of the season was enough to maintain Barnet's push for the Nationwide Conference title and leave Northwich Victoria struggling to get out of the relegation zone.
Grazioli, the division's topscorer, struck after just five minutes in a scruffy game at Underhill.
Barnet were good value for the win, but never really got going against a Northwich team that battled hard but had little to offer.
The home side started brightly with their first move of the game forcing a corner. Simon King swung in a left-footed cross that wad headed on by Chris Plummer for Grazioli to get the faintest of touches.
Grazioli nearly made it two after a powerful run and throughball from Liam Hatch, but the impressive Andrew Ralph was out quick to snuff the danger.
It wasn't until the 20th minute that Northwich strung a decent passing move together and created a chance, but Jonny Allan shot without conviction.
The powerful Ian Hendon then went close on the stroke of half time with a stunning drive that Ralph did well to turn around for a corner.
Within 60 seconds of the restart Ismail Yakabu earned a penalty after being upended by Mark Foran.
Grazioli struck the ball hard and low only to see Ralph dive to his right and made a superb stop.
After that the game deteriorated, both sides happy to punt balls forward. Northwich in particular were toothless.
There was a long wait in the final five minutes while Plummer was treated for a cut to the head, but Barnet remained calm and never looked like conceding a goal.
Bees manager Martin Allen said: "We will take a 1-0 win every week. We won the game and took three points, we never looked like conceding a goal and I was pleased with the keeper keeping a clean sheet.
"This was a very difficult game for us, they well organised, but we did okay and are well placed for November."