Nathan Blissett and Dan Sparkes did the damage as the Spireites suffered just their third loss in 17.
Town were off the pace at York Road and lacked the energy and creative spark we are used to seeing under manager James Rowe.
Far too many players were not at the races and the hosts claimed a well-earned three points.
Here are Liam Norcliffe’s player ratings from the game...
1. Grant Smith 6
Nothing he could do about Maidenhead's two goals. Handling was good on a couple of other efforts. Kicking struggled in the wind in the first half. Photo: Dean Atkins
2. George Carline 5
A couple of long throws came to nothing in the first half. Not quite at it and up against a tricky player in Sparkes. Not his usual high standards. Photo: jason chadwick
3. Will Evans 4
Captained the side on his return to the starting line-up in place of Kerr. Didn't take his chance to impress and wasn't switched on for the first goal. Photo: Dean Atkins
4. Gavin Gunning 6
Had a good battle with Blissett but came out second best. Did his best to motivate and encourage. Very vocal. Photo: Phil Tooley