Bottom club Sunderland earned a stunning win at Chelsea that severely dented the Blues’ title hopes and gave leaders Liverpool a major boost, while a Wilfried Bony penalty in stoppage time ensured Swansea crept closer to Premier League safety.
Connor Wickham followed up Marcos Alonso’s shot to equalise after Samuel Eto’o had given Chelsea the lead.
After several Chelsea chances, Sunderland were given a penalty when Cesar Azpilicueta fouled Jozy Altidore.
And Fabio Borini scored to inflict Jose Mourinho’s first home Premier League defeat in 78 games as Chelsea manager.
The award of the penalty caused anger on the Chelsea bench and Mourinho had to restrain assistant coach Rui Faria, who was seeking to confront referee Mike Dean.
Faria was sent to the stands to watch the final stages as the match – and quite possibly Chelsea’s chances of winning the league – fizzled out.
The shock result leaves the second-placed Blues two points behind Liverpool, who will play their game in hand against Norwich on Sunday before hosting the Blues a week later.
Meanwhile, Sunderland, who had secured a point at title-chasing Manchester City in midweek, closed to within three points of Norwich, who are occupying the final spot above the relegation zone.
At St. James’ Park a Wilfried Bony penalty in stoppage time ensured Swansea crept closer to Premier League safety and increased the pressure on Alan Pardew’s Newcastle.
The Magpies, lacking confidence after four successive defeats, took the lead against the run of play thanks to Shola Ameobi’s finish into the bottom corner.
But Bony headed home from a Ben Davies corner to level before the break.
The match seemed to be petering out but Marvin Emnes was felled by Cheick Tiote and Bony struck from the spot, reports the BBC.
And Crystal Palace made sure of Premier League survival as Mile Jedinak’s penalty beat West Ham to secure a club-record fifth straight top-flight win.
The Eagles had a penalty appeal turned down after the ball hit Kevin Nolan’s shoulder, but almost fell behind to Andy Carroll’s header before the break.
Carroll fluffed a shot when well placed and paid the price when Pablo Armero tripped Cameron Jerome in the box.
Jedinak converted and Joe Cole shot wide as a poor West Ham came up short.