Chelsea's unbeaten run in the current season finally came to an end as they succumbed to a shock 1-2 defeat to ten-man Newcastle despite putting up a good fight.
Substitute Papiss Cisse's brace proved to be the difference as the Blues were only able to manage a late consolation through Didier Drogba.
While Newcastle boss Alan Pardew made five changes following his side's 1-1 draw at Burnley on Tuesday, Jose Mourinho made two alterations, bringing in Diego Costa and John Obi Mikel in place of Drogba and Nemanja Matic.
The game started with the visitors dominating possession before creating a couple of chances.
However, both were wasted as Willian failed to hit the target on both occasions. While his 10th minute shot, following some good work from Eden Hazard and Costa, was well wide, the Brazilian again failed to get his curling effort on target after eight minutes.
The Magpies, who were pretty quiet in the opening stages, finally started finding their feet as Jack Colback forced a good save from Thibaut Courtois at the half hour mark.
The final chance of the first half fell to Willian in the 41st minute but he failed to trouble Rob Elliot, who managed to make a pretty comfortable save to deny the Brazilian.
Things did not start well for Newcastle in the second half as Elliot, who picked up an injury, was replaced by 21-year-old Jak Alnwick.
Still it was the hosts who took the lead in the 57th minute through Cisse, who found the net with the simplest of tap-ins after Gary Cahill failed to clear a low cross from Sammy Ameobi.
Chelsea, who seemed alarmed after going behind, started to desperately looking for an equaliser as Mourinho introduced Andre Schurrle and Drogba into the attack.
Some very good defending from Fabricio Coloccini and Ryan Taylor prevented Costa from levelling the scores in the 76th minute, before Hazard saw his effort thunder against the post a couple of minutes later.
As Chelsea sent everyone forward in search of the equaliser, Newcastle caught them on the break which eventually resulted in them doubling their lead through Cisse in the 78th minute.
Colback sent the ball towards Moussa Sissoko and the Frenchman in turn picked out Cisse, who made no mistake as he slotted the ball past Courtois.
Chelsea's hopes of maintaining their unbeaten start to the 2014/15 Premier League campaign got a boost when Taylor was sent-off (following a second yellow) for fouling Schurrle, and Drogba found the nets from the resulting free-kick in the 83rd minute.
But the Magpies managed to hold their nerve and hang on to the lead, as Chelsea suffered their first defeat of the season.