Goals from Jon Stead, James Hanson, Billy Knott and Andy Halliday were enough to propel Phil Parkinson’s men through to the FA Cup fourth round and a glamour trip to Premier League leaders Chelsea.
It was no more than the Bantams deserved against a Championship outfit who lost their discipline long before the tie itself as Marc Beevers was sent off inside just six minutes for a professional foul.
The Lions, who had been so desperate to secure their own grudge match against Chelsea in the next round, then sparked an ugly first-half melee that ended with goalkeeper David Forde somehow being shown a yellow card and not red despite clearly punching two Bradford players.
Referee James Adcock compounded his leniency by sending both Phil Parkinson and assistant Steve Parkin to the stands for questioning why Forde had not followed team-mate Beevers in being dismissed.
Not that this unduly affected Bradford, who were never going to be denied a money-spinning trip to Stamford Bridge on January 24 that now replaces the scheduled trip to Swindon Town, meaning the ‘joy’ of having to negotiate the ‘magic roundabout’ that has been confusing drivers outside the County Ground for more than 40 years can be put off until a later date.
The two clubs had met twice in the FA Cup before last night, the Londoners progressing at the expense of the Bantams in both 1914 and 2006.
Any chance of the Lions making it a hat-trick of successes, however, had all but disappeared within the opening 18 minutes as Beevers saw red and City raced into the two-goal lead.
The dismissal came first, the former Sheffield Wednesday defender guilty of hauling down James Hanson as the last man.
Referee Adcock, for what by the final whistle would feel like the first and final time, got the decision spot on and City soon made their numerical superiority pay.
Hanson was again the key figure, heading in at the far post to open the scoring after Halliday’s out-swinging corner on eight minutes had been flicked into his direction by Rory McArdle.
The second goal arrived 10 minutes later and, again, it was a set-piece as Filipe Morais’s free-kick was diverted into the path of Stead by Andrew Davies and the Huddersfield-born striker did the rest with a sweet finish.
By now, Bradford were rampant and the hosts went further ahead just before the break when Halliday tapped in after a fine dart down the right flank and cross from Morais.
The game was up for the Lions, who had been guilty of some awful ill-discipline just before the half-hour that somehow didn’t result in the visitors being reduced to nine or even eight men.
A blatant shove by Alan Dunne on Hanson that led to the striker clattering into the advertising hoarding sparked a melee that saw players from both sides square up to each other.
Goalkeeper Forde, after racing 25 yards to get involved, was the chief agitator with a right hook on Stead that was followed by another punch being thrown at Billy Knott.
How such blatant thuggery led to Adcock showing just a yellow card to Forde is a question only the official can answer.
Dunne was also fortunate not to walk for sparking the trouble, the defender joining Knott in being booked once calm had been restored.
To add insult to what could have been serious injury for either Knott or Stead, Adcock then preceded to send Parkinson to the stand along with his assistant Parkin.
Any fears, though, that City might suffer without their management duo were soon allayed as goalkeeping coach Lee Butler and fitness coach Nick Allanby conducted matters from the dugout to ensure the hosts continued to take the game to Millwall.
Three goals ahead at the break, Bradford were denied a fourth two minutes after the restart when Forde blocked a Knott shot that had followed excellent work by James Meredith.
Knott, however, would not be denied and he duly made it 4-0 just before the hour after latching on to a mix-up between Danny Shittu and a team-mate.
Halliday then shot narrowly wide from 25 yards as the irate 611 visiting fans, their dreams of storming west London later this month at an end, chanted ‘you’re getting sacked in the morning’ at manager Ian Holloway.
Substitute Francois Zoko hit a post and then brought a flying save from Forde as the Bantams finished strongly to the delight of the home fans in the 11,859 crowd.
Bradford City: Williams; Darby, Davies, McArdle, Meredith; Morais, Knott (Yeates 73), Liddle, Halliday; Hanson (Routis 80), Stead (Zoko 69). Unused substitutes: Urwin, Sheehan, Kennedy, Webb-Foster.
Millwall: Forde; Dunne, Shittu, Beevers; Martin (Gueye 63), Abdou, Chaplow, Briggs; Upson (Webster 46); Fuller (Woolford 23), Gregory. Unused substitutes: King, Powell, McDonald, Nelson.
Referee: J Adcock (Nottinghamshire).