Chelsea 2 Bradford City 4

On a fourth round day full of shocks and surprises in the FA Cup, perhaps the greatest one of all was reserved for Jose Mourinho's men at Stamford Bridge. After seemingly coasting into a two goal lead during the first-half, Chelsea somehow engineered a humiliating home defeat against League One side Bradford City, as this year's competition was blown wide open.

In the build up to the match, Mourinho had indicated that it would be an embarrassment to lose to Bradford, especially with the manner in which the Blues had begun their campaign both domestically and in Europe this season.

Yet that was precisely what they managed to do. Old head Jon Stead was responsible for much of the damage inflicted on the home side, scoring one and providing assists for two others. His hold up play in particular was a reminder of the good old days when he used to strut his stuff in the top division with Blackburn Rovers and Sunderland. Currently on loan to Bradford from his home town club Huddersfield, he seemed to relish being back among the big boys again.

The visitors started encouragingly, Andrew Davies' flying header being saved by second choice (these days) Petr Cech, before Chelsea seemed to settle into their usual form at the Bridge. They took the lead through Gary Cahill on 21 minutes, the England centre-half flicking in a near post header from a corner.

That became two with seven minutes to go to the break as Ramires scored with a neat left foot finish, after neat interplay with team mate Mohamed Salah.

Just as it was threatening to become an all too familiar story in recent weeks for the Blues at home, Stead began to turn the match back in Bradford's favour with a powerful left foot shot that Cech could not keep out, to reduce the arrears before the break.

Bradford continued to push on into the second period, roared on by their travelling support of around 6,000 fans, with Stead a constant threat and menace to the Chelsea back line. They got their reward on 75 minutes as Filipe Morais netted the unexpected equaliser, a particularly sweet moment for a player released by the London club.

The goal seemed to rouse Chelsea from their slumbers, yet Bradford were not settling on a replay and showed little sign of being overawed by their esteemed opposition. It was still something of a shock though when they took the lead, Stead turning provider for Andy Halliday to fire his right-foot shot into the corner of the net.

The seven-time winners were handed seven minutes of stoppage time to save themselves, but it only got worse for them, as Stead again held the ball up perfectly to tee Mark Yeates up to finish the tie off. Cue delirium in the Bradford supporters' end and 'disgrace' for the Premier League leaders, at least in Mourinho's view afterwards. Phil Parkinson by contrast was understandably delighted with his men's efforts and performance as they continue to battle on against the odds in the famous cup competition.

The Bantams go into the draw for the fifth round for the first time in 18 years and end the aspirations of Chelsea for the quadruple, that some had been believing might be possible this season. Mourinho had made nine changes to his starting XI, perhaps with one eye on the second-leg of their Capital One Cup match on Tuesday against Liverpool, but was still able to field a strong side. He will now hope that it does not backfire on him, as the defining moments of his side's season begin to unravel.