Bradford extended Burnley's uncomfortable start to the season with a 4-2 penalty shoot-out win after their second-round Carabao Cup tie had finished goalless at Valley Parade.
Jon McCracken saved from Jacob Bruun Larsen after Zeki Amdouni had hit the post with the first spot-kick.
Burnley head coach Nicky Hayen had made nine changes from the side beaten at West Brom on Sunday and they were on the front foot from the start, forcing the first save as McCracken tipped over a well-struck drive from Connor Roberts.
The midfielder tested McCracken with another shot from 25 yards but it flew straight at the home keeper.
Bradford, who had not conceded a goal in their first three games, defended solidly against the Championship club's pressure and Reece Welch denied Zeki Amdouni from close range.
Former Burnley midfielder Adam Phillips had Bradford's first chance but lifted Jake Beesley's cross over the bar.
The home side asked a lot more questions after the break with Gregoire Coudert saving from Adam Phillips and Josh Laurent clearing Macaulay Gillesphey's header off the line.
McCracken denied Laurent and Ugo Raghouber volleyed over as the game became more open.
The 'keeper saved again from Laurent before the League One side won the penalty decider.
