A 1-0 win over Doncaster Rovers was enough for the Bantams to book their place in the semi-finals of the Bristol Street Motors Trophy.
City had the better of the play in the first half but could not find a goal, with Jake Young going closest on his first start of the season in claret and amber.
But a second-half free-kick from Harry Chapman and some solid defending was enough for the Bantams to progress into the final four of the competition for the first time in their history.
City started brightly, with Andy Cook seeing a snapshot saved by Louis Jones before the visitors had even touched the ball.
Doncaster nearly scored themselves moments later after Joe Ironside was first to a flick on but his header dropped wide.
Young received the ball just inside the box in the 20th minute, and had three bites of the cherry as each effort was blocked before the ball dropped behind for a corner.
Halfway through the opening period, player of the match Kevin McDonald floated a brilliant delivery into the box and straight to the feet of Brad Halliday, whose effort was well saved at the near post.
City had the better of the first 45, and from their kick-off in the second Doncaster looked to create early. An effort from the edge of the box by Owen Bailey forced Colin Doyle into a strong save down to his left.
Minutes later, the ever-lively Lewis Richards found the ball inside the box and smashed an effort from a tight angle towards the goalkeeper's near post, which was well saved.
City thought they had taken the lead in the 50th minute as Cook rose highest to nod a header goalwards. The home faithful thought it had crossed the line, but the assistant referee stopped the debate with a raised flag for offside.
The Bantams deservedly broke the deadlock just before the hour mark, as Alex Gilliead drove into space on the edge of the area before seeing his run cynically halted by Jay McGrath, who dragged him back.
The foul presented a free-kick on the edge of the area in striking distance. Chapman stepped up and sent a wicked effort around the wall and into the bottom corner.
With just over 10 minutes to go and after some astute defending inside the City box, Young was able to break.
He beat three Doncaster defenders and laid it off to Richards but his eventual cross went over Cook’s head.
Late on, Cook was given his marching orders after a second yellow card for a foul on Owen Bailey, meaning he will the semi-final.
Doncaster threw bodies forward in their search to rescue an equaliser with an extra player and take the tie to penalties, but the Bantams stood firm to book their place in the hat.
CITY: Colin Doyle, Brad Halliday, Matty Platt, Andy Cook, Alex Gilliead (C), Ciarán Kelly, Harry Chapman (Clarke Oduor 68’), Kevin McDonald, Jake Young (Sam Stubbs 90+1'), Jonathan Tomkinson, Lewis Richards (Liam Ridehalgh 89’). SUBS NOT USED: Zac Hadi, Tyler Smith, Bobby Pointon, Adam Wilson.
GOALS: Harry Chapman (58’).
DONCASTER: Louis Jones, Jamie Sterry, James Maxwell (Jack Senior 68’), Richard Wood (C), Luke Molyneux (Jon Taylor 35’), George Broadbent (Joseph Olowu 68’), Owen Bailey, Joe Ironside, Conor Carty (Kyle Hurst 45+1’), Jay McGrath, Ben Close. SUBS NOT USED: Ben Bottomley, Tommy Rowe, Will Flint.
ATTENDANCE: 3,086 (with 468 travelling Doncaster Rovers supporters).