The depleted hosts, who had lost the influential Michael Olise, Eberechi Eze and Marc Guehi to injury, took the lead via a Jefferson Lerma screamer – his maiden Eagles goal.

Gallagher equalised almost immediately after a delayed start to the second half, firing home his first of the Premier League season in the 47th minute.

Just as it seemed the relegation-threatened hosts were close to securing a valuable point, Gallagher struck in his second on the stroke of normal time, moments before Enzo Fernandez ensured Chelsea would end the evening in the top half of the table.

It was difficult to predict what kind of reception Palace would receive after the 4-1 loss at rivals Brighton, after which some players and fans in the away end exchanged heated words, and the frequent appearance of protest banners in recent weeks.

And though several were raised ahead of kick-off – "supporters ignored and taken for granted" among them – the overall mood was perhaps less sour than boss Roy Hodgson, who had pleaded with supporters to back his diminished side, might have expected.

His players responded with an encouraging start, despite the visitors enjoying the lion's share of possession, pouncing on loose balls with promising drives into Chelsea's final third.

Palace took the lead at the half-hour mark, shortly after Jean-Philippe Mateta had missed a chance to fire the hosts ahead, when Lerma managed to liberate himself from a quartet of tumbling and battling bodies and patiently took a few paces forward before blasting the ball high into the net from 25 yards out.

Former Eagles loanee Gallagher, who scored the winner in the October 2022 edition of this fixture, fired wide of Dean Henderson's left post before the break, by which the Blues had completed 420 passes but not registered a shot on target.

The second period got off to a delayed start after referee Michael Oliver experienced technical issues, the stadium singing and laughing along as Bob Marley's ‘Three Little Birds (Everything's Gonna Be Alright)' was pointedly played in the pause.

It proved to be an ironic choice when Gallagher side-footed Malo Gusto's delivery past Henderson in the 47th minute and the away end immediately began taunting the home support with their own version of the famous reggae refrain, including an emphatic “Chelsea”.

Although a livelier and more disciplined Blues side had emerged for the second half, the hosts were not without their chances. Thiago Silva slid to deny Mateta and Daniel Munoz, in his first home start, tested goalkeeper Djordje Petrovic from a tight angle.

Ben Chilwell cringed after blasting a good chance over the crossbar, close enough to lure Henderson into a leap as Chelsea continued to apply pressure.

With just under 15 minutes remaining in normal time, Matheus Franca forced Petrovic into a good diving save, before Cole Palmer was denied by Henderson soon after.

Palace survived another Chelsea set piece and, with less than 10 minutes to go, were able to crowd substitute Raheem Sterling, nearly set up for a dangerous chance from Palmer's cross.

Both sides pushed for more and, just as it seemed like Palace had clung on for a vital point, Palmer picked out Gallagher who, in a deja-vu moment for the home support, swept Chelsea into a 90th-minute lead.

Any hope of a late Eagles reply was dashed in added time when Fernandez took his time before firing into the top left corner. Palmer again provided the assist.

Conor Gallagher and Enzo Fernandez save Blues' blushes with late strikes against Crystal Palace