Palace clinched their first win at Stamford Bridge in the league since 1982 as goals from Bakary Sako and Joel Ward stunned the reigning champions and continued the Eagles’ brilliant start to the season.
After a goalless first half the Malian winger scored for the second consecutive game to hand his side the lead, but when Radamel Falcao grabbed an equaliser it looked like a point would be on the cards.
However Ward popped up two minutes later with a header to secure a famous win for Alan Pardew’s side to inflict just the second league defeat of Jose Mourinho’s tenure at Chelsea in what was his 100th game in charge at Stamford Bridge.
It was a magnificent display by all wearing Palace shirts as they put in another fine performance on the road to once again send the noisy travelling hordes of Palace fan home happy.
The opening 15 minutes began promisingly for the visitors after they forced three early corners, and although they came to nothing they were also restricting their opponents to wayward efforts from distance, with Branislav Ivanovic and Willian both troubling the Eagles fans in the Shed End’s top tier.
However the champions did go close four minutes later when Willian picked out Pedro on the right and the new recruit was given plenty of time to get the ball under control and fire towards the top corner from just outside the box but his strike flashed wide.
Palace responded when Wilfried Zaha picked out Sako on the left and the Malian sped towards goal before unleashing his thunderous left foot which caused Thibaut Courtois to save with an outstretched boot, with Yohan Cabaye blazing the resulting corner well over.
And on 28 minutes the French international should have put his side ahead. After some slick passing Zaha weaved his magic inside the area and drew in three Chelsea defenders, which allowed an undetected Cabaye to break into space before being found by the winger, but he hit a glorious one-on-one opportunity straight at Courtois.
Palace were on top of the game at this point and Sako dragged a shot well wide, and with the home fans getting restless Gary Cahill was next to ambitiously balloon a shot off target from 30 yards.
They did go close though when a goalmouth scramble ensued four minutes before half-time. Diego Costa initially forced Alex McCarthy into his first save, with the rebound falling to Cesc Fabregas. The Spaniard saw his low effort blocked by a combination of the keeper and Scott Dann, before a melee occurred which saw a grounded Damien Delaney crucially flick the ball away from the waiting Pedro.
Half-time came and went but Palace continued to look threatening and nearly got lucky when when an Ivanovic clearance struck Cahill but the former managed to hook the ball away before it crossed his own line, and Sako once again tested Courtois with a low skidding shot that the Belgian got down to.
Delaney was playing like a man possessed and having battled to keep Costa quiet during the first hour would put his body on the line three times within 10 seconds to block three attempts at his goal, and then deflected a Pedro attempt wide, with Sako heading off his own goalline after Cahill got his head to the resulting corner.
But all that defensive resilience paid off when the Eagles snatched the lead on 65 minutes. Pape Souare cutely played in Yannick Bolasie who squeezed the ball into the area towards Sako. The winger saw his first shot blocked by a sliding challenge by Cesar Azpilicueta, but he lashed the rebound in to score his second goal in his second appearance for the club.
The returning Bolasie then had a couple of opportunities to put his side further in front, firing a great low cross by Sako wide before getting the ball on the left and shaping to find the top corner but watched his attempt just head over with Courtois beaten.
But the missed opportunities looked like they would haunt Palace as with 12 minutes to go the Blues drew level. Fabregas picked out Pedro with a fine pass on the right and he put in an equally brilliant cross for Falcao to bury past McCarthy with a near post diving header.
But unbelievably Palace got back in the lead less than two minutes later. Bolasie once again caused mayhem down the left and found Sako at the back post, and he cleverly picked out Ward who flew in to head the ball into the net and send the travelling fans wild.
As Chelsea began to get desperate and pump balls into the box in search of another equaliser, some determined defending by Palace ensured they’d emerge victorious despite five minutes of injury time and clinch yet another win that will live long in the memory.
Chelsea: Courtois, Ivanovic, Cahill, Zouma, Azpilicueta (Kenedy 68), Matic (Loftus-Cheek 73), Fabregas, Pedro, Willian (Falcao 65), Hazard, Costa. Subs not used: Begovic, Baba Rahman, Mikel, Remy.
Palace: McCarthy, Ward, Dann, Delaney, Souare, McArthur, Cabaye (Ledley 82), Zaha (Bolasie 55), Puncheon, Sako (Lee 84), Wickham. Subs not used: Hennessey, Mariappa, Mutch, Gayle.