Grantham Town held league leaders North Ferriby United to 1-1 at half time, but crumbled after the break to go home defeated.
United went in front through Anthony Wilson on 29 minutes.
The Gingerbreads levelled the affair four minutes before half time when Kallum Smith struck home.
But the home side restored their lead six minutes after the break when Ryan Kendall scored.
Wilson bagged his second to seal the win for North Ferriby in the 74th minute.