VAUXHALL'S League Challenge Cup hopes hang in the balance after last night's defeat and any possible progress to the next round depends on the results of others.
The Motormen, who were previously unbeaten in this year's competition, needed just a point to qualify but failed to warm to the frosty conditions.
Manager Alvin McDonald said: 'I did not think that the pitch was playable and people were sliding around. I'm not happy with the referee's decision but the simple fact is we can't defend set pieces, it's getting to the stage where it is not good enough.'
Vauxhall held their own in the first half and although Altrincham just shaded the play, it was the Motormen who had the best chance to score.
Jon Stanhope found some space on the right hand side of the home penalty area but his low cross to the back post went wide after hitting Nicky Young's shin from close range.
Altrincham snatched the lead just three minutes after the re-start as Daniel Murphy's header across the goal was nodded in by Rod Thornley from a couple of yards out.
On-loan Paul Aldridge was at the hub of most of Vauxhall's attempts to draw level.
But it was Altrincham who went on to score again on 63 minutes as Murphy headed in Neil Ryan's free kick from the right touchline.
Vauxhall: Holmes, Spellman (Fearns 70), Thompson, Brazier, Haddrell, Lynch, Aldridge, Lawton, Stanhope (Cullen 68), Young, Wright.