Despite a good start to the game, the Gingerbreads ended up well beaten at Bamber Bridge.
The home side kept passing and moving the ball around well and two goals in two minutes midway through the second half turned the game against Grantham.
"We were nowhere near good enough today." Said Gingerbreads Manager Richard Thomas. "We said at half-time that a one goal lead flattered us. We weren't close and have a lot of work to do. Old habits jumped back out and we have got to stop that if we are going to get results."
Things couldn't have started better for Grantham. After five minutes, referee Mr Atkinson gave a penalty for a push on Bradley Fortnam-Tomlinson. Shaun Harrod blasted the spot kick down the middle to give Grantham the lead.
Fortnam-Tomlinson and Danny Durkin had chances to extend the Gingerbreads lead in the next ten minutes, but neither took their chance. Fortnam-Tomlinson shot wide from 25 yards out, before Durkin turned Phil Doughty and tried to lob Lloyd Rigby, only to see his effort drop just wide with Rigby beaten.
From that point on, the home side got on top, but for an hour, Grantham defended well and protected their goal well. Matt Lawlor and Alistair Waddecar both had chances blocked by the Gingerbreads back four. Late in the first half, Chris Marlow and Callum Spooner also had chances, but missed the target.
A bright start to the second half from the Gingerbreads proved a false dawn. Fortnam-Tomlinson lifted an effort over the bar and Ross Barrows created half chances, but the home side gave nothing away inside their own penalty area.
Waddecar and Dawson began to exert an influence on the game for the home side. Their passing and movement kept the Gingerbreads pressed back. Both tried their luck before they turned the game on it's head with a goal each in two minutes.
Waddecar had two chances that the Gingerbreads back four blocked before the home side levelled. Dawson laid the ball for Waddecar to hit a shot that Jordan Wright did well to parry. Dawson reacted quickest to put the ball past the Gingerbreads keeper for this Bamber Bridge equaliser.
A minute later Grantham were behind. A good cross was headed goalward by Waddecar. Wright saved his effort, but Waddecar got to the ball first and put the home side in front.
Grantham's afternoon was made worse in injury time. Substitute Luca Navarro took the ball under control neatly by the corner flag. He turned inside and breezed past three challenges on the bye-line before sliding a shot past Wright from a narrow angle.