Luisma Villa’s 80th minute strike saw Barnet make it two wins from two under Uli Landvreugd and Dick Schreuder.
The Bees dominated from start to finish but they had to overcome a rigid Tamworth defence and incredibly tough conditions at The Hive.
The Lambs had a penalty saved by Nick Jupp in the first-half and it looked like ending level but Villa converted with time running out before Kieron Cadogan and Jake Hyde had goals chalked off for offside.
Watch Juppy’s save below or for extended highlights click here.