A series of decisions by the match officials denied the Gingerbreads at least a point which they thoroughly deserved.
Penalties and free kicks not awarded changed the result in favour of the home side.
In the second minute, Lee Shaw got away from the Altrincham defence. Home goalkeeper Anthony Thompson raced off his line to challenge, forcing Shaw to hurdle him to avoid a collision. Shaw went to ground, but referee Mr Swallow saw it as a dive and booked the Gingerbreads striker rather than award a penalty.
The game settled into a high quality game with both sides playing good football. Danny Meadows and Olly Luto both had chances, but missed the target. Mr Swallow frustrated the Gingerbreads again on 30 minutes. Jordan Hempenstall's cross struck Joel Jenno-Leto on the arm from 5 yards away, but despite a clear view, Mr Swallow did not see it as a penalty.
Kieran Preston made a good save seven minutes before the break. Tom Peers played in Josh Hancock, but Preston denied the home striker. Michael Hollingsworth was maybe fortunate to stay on the pitch just before half-time. Twice in five minutes he was slightly late on challenges. Fortunately for Hollingsworth, the second challenge only saw a warning from Mr Swallow when he could have shown a second yellow card.
The controversies continued after the break. Just four minutes into the second half, Altrincham won a corner. With the ball in the air inside the six yard box, Preston was twice obstructed, but Mr Swallow let play run and Jordan Hulme poked it home for what turned out to be the decisive goal.
Lee Shaw had the ball in the net after 66 minutes. He got on the end of a flick on and turned the ball in, only to see an offside flag raised to the surprise of most in the ground.
As Grantham pushed forward and had the better of the game late on, Altrincham defended strongly and denied the Gingerbreads clear efforts on goal. Chances came for the home side on the break. Preston saved well from John Johnston had space to shoot. The same player missed the target in injury time as the home side held on.