The Hatters lost at Edgeley Park for the first time in four games as Tamworth leapt above them in the Blue Square Premier table thanks to a first half penalty from Adam Cunnington.
In an open first quarter of an hour both sides created chances. County were quick to look for an early goal with Jon Nolan and the recalled Mark Cullen having efforts blocked in the opening two minutes.
Tamworth came close with Sam Oji shooting wide from a loose ball following their first corner whilst Tom Marshall headed just wide from a free kick with Richard O'Donnell rooted.
Tony Breeden saved a Nolan free kick comfortably with Jake Hessenthaler shooting narrowly wide for the visitors.
The only goal of the game came in the 16th minute as Cunnington blasted home from the spot after Jonathan Thorpe tumbled over Sean Newton's outstretched leg in the area, referee Whitely quick to award a penalty kick.
Good play from Matt Mainwaring through the middle of the park freed up Cullen on the left, his cross being headed out for a corner by Oji. From Newton's corner Danny Hattersley appeared to be bundled to floor as the ball came across, no penalty being given.
As the half came to a close the Hatters struggled to play the type of football that they had been playing over the past few weeks, Tamworth quick to force errors whilst looking dangerous on the break.
The visitors missed a good chance to double their lead just before the break after good play down the County right from Cunnington, his cross finding strike partner Tommy Wright who headed wide when well placed.
HT: Stockport County 0 Tamworth 1
Darije Kalezic made two changes for the start of the second half with Simon Hackney and Adnan Cirak replacing Mainwaring and Hattersley.
In a very nervy start to the half by County, O'Donnell made a superb save from Hessenthaler to stop the visitors taking two goal lead after Connor Gudger had raced through a static defence before finding the young midfielder in the 6 yard box.
The big County keeper was in action soon after with a brilliant double, making a diving block to stop Wright tapping home from his original save from Lloyd's shot from the edge of the box.
Hackney forced Breeden into a smart save after the winger had cut in from the right to curl an effort goal wards, the winger seeing another effort fly just wide a minute later.
In a spell of better play from County they broke down the left through Hackney and Newton before Jordan Fagbola clipped a neat ball over the top to Cullen who's quick control and shot was saved superbly by Breeden.
A quickly taken free kick by Johan Hammar to Cullen who in turn found Cirak on edge of box, the Swede cutting inside before seeing his effort blocked by Connor Gudger.
The visitors were happy to hit County on the break and another good move down the right ended with another save from O'Donnell as he turned Wright's shot onto the post.
With time running out Andy Halls blazed an effort over the bar after Sam Sheridan's free kick had been knocked down by Fagbola, Breeden tipped Newton's free kick onto the post, with Hackney denied a debut goal as Marshall cleared his snap shot off the line. Referee Whiteley adding salt into the Hatters wounds as he denied Nolan a certain penalty on 88 minutes, the midfielder being hacked down in the box as he raced onto a neat through ball from Sheridan
FT: Stockport County 0 Tamworth 1
Starting XI: O'Donnell, Halls, Newton, Hammar, Tunnicliffe (Macken), Hattersley (Cirak), Sheridan, Cullen, Nolan, Fagbola, Mainwaring (Hackney).
Subs: Ormson, Whitehead, Cirak, Macken, Hackney.
ATT: 2,732 (52)