LONDON (Reuters) - Often derided and disrespected during the Premier League era, the FA Cup added another incredible chapter to its proud heritage on Saturday as Chelsea and Manchester City were humbled by supposed inferiors.
A day after Manchester United suffered a fright in a 0-0 fourth-round draw at fourth tier Cambridge United, Premier League leaders Chelsea surrendered a two-goal lead to lose 4-2 at home to third tier Bradford City.
If that was not a seismic enough shock, a couple of hundred miles north, Premier League champions City were torn apart by second tier promotion hopefuls Middlesbrough, crashing 2-0 at a stunned Etihad.
Chelsea were unbeaten in all competitions at home this season. They boast a 100 percent record in the league at Stamford Bridge and appeared on course for a routine win after 38 minutes with goals from Gary Cahill and Ramires.
Bradford, 49 places lower than Chelsea and with a squad made up of journeymen and bargain signings, had other ideas.
They gained a foothold when Jon Stead fired a beauty past Petr Cech before halftime.
Former Chelsea player Filipe Morais side-footed an equaliser after the break before an improbable script was completed by Andy Halliday thumping the ball past Cech with 10 minutes left and Mark Yeates side-footing a fourth in stoppage time to send the visiting fans delirious.
Chelsea manager Jose Mourinho visited the opposition dressing room to offer his congratulations but was scathing of his side, which despite nine changes from Tuesday's League Cup semi-final first leg draw at Liverpool, was packed with internationals.
"Me and the players must feel ashamed," Mourinho told the BBC as his hopes of a quadruple this season were extinguished in the most unexpected circumstances.
"It's a sporting disgrace. This happens to every team from time to time but for me it’s the first time, it's unacceptable to lose against a team from a lower league."
It was the first time in England that a Mourinho team lost to lower league opposition.
"The lads are absolutely bouncing in that dressing room and what they've done today will be remembered for a very long time," said Bradford manager Phil Parkinson who led the Yorkshire side to the 2013 League Cup final against the odds.
Manchester City only arrived back from a warm-weather training camp in Abu Dhabi the evening before taking on Middlesbrough and looked groggy against fluent opponents who struck after halftime through Chelsea loanee Patrick Bamford and Spaniard Kike.
Bamford bundled in the opener after sloppy defending and, after Boro wasted several clear chances and Frank Lamaprd hit the post for City, Kike beat keeper Willy Caballero with a neat finish after a counter-attack.
City's second home defeat in a week after losing to Arsenal last Sunday has derailed their season.
"We had six or seven clear chances to score. We played well in the first-half," said City boss Manuel Pellegrini.
"After they scored we were disordered, they had a counter attack and they scored again late on."
The surprises, that begun earlier in the day when top flight Swansea City lost 3-1 at second tier Blackburn Rovers and had two players sent off, continued when Southampton went down 3-2 at home to Crystal Palace, meaning the top three in the Premier League all crashed out on a remarkable FA Cup afternoon.
Jeffrey Schlupp's stoppage-time volley gave Premier League bottom club Leicester City a surprise 2-1 victory at League Cup semi-finalists Tottenham Hotspur.
West Bromwich Albion avoided an upset at Birmingham City, winning the Midlands derby 2-1, but a poor day for the elite continued when Bolton Wanderers drew 0-0 at Liverpool and Sunderland were held 0-0 at home by Fulham.
Derby County beat Chesterfield 2-0 while Preston North End and Sheffield United drew 1-1.
(Editing by Tony Jimenez)