Barnet cemented their play-off hopes thanks to super sub Liam Hatch's winner at Underhill.
Hatch got on the end of Ian Hendon's free-kick to give the Bees three deserved points against a poor Tamworth side.
Barnet dominated the first half but couldn't make their superiority count.
In the sixth minute, an Ian Hendon free-kick was nodded on by Ismail Yakabu only for Matt Redmile to shoot narrowly over.
Then Joe Gamble's exquisite throughball cut between the two central defenders and Ben Strevens rifled a shot past James Lindley from 25 yards.
But the goal was ruled out by the linesman, who gave a marginal offside decision.
Brian Quailey was left to forage up front on his own by Tamworth as the visitors flooded midfield and tried to hit the Bees on the break.
But Lambs spent the half on the back foot and in first-half injury-time, Barnet could have had a penalty as a goalmouth scramble lead to cries of handball. The referee however was unmoved.
The score was somehow still level at the break, but it didn't take long for the home side to pull ahead.
Another long free-kick from Hendon was headed on by Giuliano Grazioli and Hatch stole in at the back post to fire the ball into the roof of the net.
It took 70 minutes for Tamworth to force Ademola Bankole into a save and when it finally happened, Paul Barnes' shot lacked conviction.
But Tamworth then enjoyed their best spell. A free-kick by Mark Cooper bounced off the wall to the feet of Marcus Ebdon whose stinging volley dipped just over the wrong side of the bar.
Strevens could have made it 2-0 in the dying minutes but Lindley saved well as the snow began to fall.
Barnet boss Martin Allen said: "It was a good win, three points and a clean sheet. We never played well, but I couldn't fault the players' effort and desire.
"Liam's goal was very positive, he has been working very hard on his finishing."
