Following the fabulous victory over Wigan Athletic in the last round of The Capital One Cup, Phil Parkinson's men produced a extraordinary giant killing by beating Arsene Wenger's Arsenal side in front of a modern record crowd of 23,971 to secure a place in semi-finals of the competition for the first time ever.
Not fazed by the announcement that Arsenal's team would be near full strength, The Bantams were quick out of the traps and within 6 minutes Nahki Wells was forcing Wojciech Szczesny into a smart save after he had got the better of Gunners' skipper Thomas Vermaelen.
Vermaelen himself was the first in his side to come close to troubling Matt Duke when he met Santi Cazorla's corner with a firm header that sped narrowly over the crossbar.
Just over a quarter of an hour into the game, City took the lead! Again Wells and Vermaelen at the centre of play, it was Wells who ran the channel before putting the ball through the Belgian's legs and forcing a foul. Gary Jones' freekick was flicked on by Will Atkinson and volleyed home by Garry Thompson to send the huge home crowd into raptures.
City almost doubled their lead shortly after; a Gary Jones' set piece again causing chaos in Arsenal's defensive ranks but this time it was a corner that was met by the head of Rory McArdle and Kieran Gibbs cleared the ball off the line.
Arsenal's first menacing attempt on goal came from young Frenchman Francis Coquelin; he foxed his way past a couple of Claret & Amber shirts before striking a low shot that came back off the post.
The Gunners were pressing for an equaliser before the break and Santi Cazorla tried his luck from distance hitting a speculative 25 yard shot that flew narrowly wide of the target.
The chance of the half fell to Gervinho and instead of hitting the back of the net with his attempt, he produced a contender for miss of the season. With a man over, Arsenal worked the ball to Kieran Gibbs who produced a fine low cross that evaded all the City back line including Duke and was tapped horrendously wide by Gervinho with the goal gaping.
On the stroke of half time, Nahki Wells almost doubled City's lead; a long ball forward was flicked on by James Hanson and Wells got the better of Vermaelen once more before stabbing a shot forward that trickled fractionally wide of the target with Szczesny beaten.
The second half was to produce a 'backs to the wall' task for Phil Parkinson's men and Aaron Ramsey was the first to try his luck in Arsenal's attempt to get back on terms; a lightning fast counter attack ended with the Welshman hitting a shot narrowly wide from the edge of the area.
Wenger's substitutes were proving effective and one linked up with another as Tomas Rosicky cut the ball back for Alex Oxlade-Chamberlain to force a fine save from Matt Duke.
Jack Wilshere was the most impressive Arsenal player on the evening and he superbly showed a turn of pace and intelligence to burst away from midfield and produce a fine long range shot that forced Duke into another smart stop.
The visitors' equaliser was coming and it eventually arrived with an agonising 2 minutes left on the scoreboard clock. Santi Cazorla's corner was cleared straight back to him and he had time and space to pick out an inch perfect cross that was bundled in at the back post by Thomas Vermaelen to lead to noisy celebrations from the 4,000+ fans housed in The Midland Road stand.
Cazorla himself almost snatched victory for his side late when he was denied twice by Duke; his dipping free kick was pushed away by the City stopper and the ball was worked back to The Spaniard who forced an outstanding low save.
As the full time whistle blew with scored level at 1-1, the task remained the same: keep Arsenal at bay.
Jack Wilshere played a fantastic one-two to bear down on goal but it was Duke to the rescue once more as he raced off his line to foil him.
Tomas Rosicky then found Gibbs in space who hit a fierce angled shot towards goal to keep Duke busy once more. Moments later, a delivery was met by the head of Bacary Sagna but Gary Jones was in the right place at the right time to clear the effort off the line.
The most notable effort of the second period of Extra-Time came from Santi Cazorla; the talented former Malaga and Villarreal star rifled an unstoppable shot towards goal from 30 yards that Duke could only watch as it cannoned back off the crossbar.
The tie headed to penalties. Not the first time that has been the case this season.
Nathan Doyle neatly tucked his penalty away via the hand of Szczesny, Gary Jones tucked away his own and Alan Connell emphatically struck his into the top corner to send Szczesny the wrong way. Duke saved from Cazorla while Chamakh and Vermaelen were denied by the post to confirm City's place in the last 4 of the Capital One Cup to send The Coral Windows Stadium into absolute euphoria.