Former Eagles loanee Conor Gallagher bookended the second half with goals and Enzo Fernandez added the finishing touches late in stoppage time to spark pandemonium in the away end at Selhurst Park as back-to-back away wins eased the pressure on Blues boss Mauricio Pochettino.
It was a sickening end to an otherwise battling performance from injury-plagued but improved Palace, who had led at half-time courtesy of Jefferson Lerma’s 25-yard wonder strike - his first goal for the club since joining last summer.
However, Palace remain 15th and just five points above the relegation zone with the scrutiny now only set to increase on under-fire manager Roy Hodgson following another galling loss.
Chelsea’s turnaround came after a wretched first half in which they enjoyed almost 80 per cent possession but had to wait until stoppage time to register their first shot in anger of the night, with Gallagher driving wide of the back post with a low strike after fast feet from Noni Madueke inside the Palace box.
Per Sky Sports, Pochettino’s side had the most successful passes without registering a shot on target of any team in any half of any game in the Premier League in the last 20 years.
Moises Caicedo and Madueke were both at fault for Lerma’s superb opener, being caught out just outside the box before the Colombian launched an unstoppable swerving strike beyond the despairing dive of Djordje Petrovic and into the top corner.
But Gallagher would come back to haunt the club for whom he starred during a hugely impressive loan spell during the 2021/22 season, rifling an emphatic half-volley beyond the helpless Dean Henderson after being teed up by Malo Gusto’s accurate cut-back straight after a delayed start to the second half caused by an issue to referee Michael Oliver’s communication equipment.
Gallagher crucially popped up again in the 91st minute after a competitive second half that saw chances for both sides, sweeping low into the bottom corner from just outside the box following an assist from Cole Palmer.
Palace then committed bodies forward in search of their own equaliser, leaving themselves open to one final attack as Fernandez, also teed up by Palmer, waited for the challenge of Daniel Munoz before lifting the ball above Henderson, like Gallagher registering his second goal in as many games following a wonderful free-kick in the 3-1 FA Cup success at Aston Villa last week.