Stockport claimed their first away win since returning to the Football League to end Bradford’s unbeaten home record.
The Hatters had lost all five of their games on the road this season but stopped the rot with a deserved 1-0 win at Valley Parade.
Antoni Sarcevic signalled Stockport’s intentions by forcing a good save from Harry Lewis after two minutes.
Harry Chapman then hit the bar for Bradford and saw another cross-shot palmed away by Stockport goalkeeper Vitezslav Jaros.
But the visitors were playing on the front foot, with strikers Paddy Madden and Kyle Wootton causing Bradford problems, and they took the lead from the penalty spot after 26 minutes.
Sarcevic was knocked over by Timi Odusina and Madden slotted home the spot-kick.
Manager Mark Hughes and assistant Glyn Hodges were both booked as Bradford grew frustrated.
Substitute Yann Songo’o poked wide from Tyreik Wright’s free-kick, but Stockport continued to defend resolutely.
And they nearly had a second goal when Ash Palmer’s close-range header was superbly kept out by Lewis, with Dave Challinor’s side good value for the victory.