The Eagles failed to make the most of several excellent opportunities as the leaders edged their way home on a night when they were far from convincing.
It was Newcastle's first league win since December 20 and although it was achieved in the face of an injury crisis - which grew with the premature departure of full-back Jose Enrique - it left the bulk of a crowd of 37,886 biting their fingernails until the final whistle.
Chris Hughton handed latest arrival Mike Williamson a start and fellow newcomer Wayne Routledge a seat on the bench, in stark contrast to the options available to opposite number Neil Warnock.
Highly-rated striker Victor Moses was pulled out of the game by the London club's administrators as they prepare to cash in on the Eagles' biggest asset, while Warnock was able to name only three substitutes.
But it was Palace who created the first opening with just four minutes gone when, despite being reduced to 10 men with defender Johannes Ertl off the pitch receiving treatment, Darren Ambrose broke and fed lone striker Calvin Andrew, who only just failed to round Steve Harper.
Ertl was replaced by Matt Lawrence seconds later, and he and his defensive colleagues enjoyed a major escape when Peter Lovenkrands could not stretch far enough to guide Enrique's driven cross home.
But the visitors should have been ahead three minutes later when Danny Butterfield met Nick Carle's cross unopposed but somehow headed wide from point-blank range.
Palace were unlucky to fall behind with 20 minutes gone, Derry guiding Andy Carroll's header past his own keeper to hand the home side the lead.
Lovenkrands fired wide on the turn within seconds of the restart and Carroll blasted a 53rd-minute effort across the face of goal.
But Neil Danns and Carle had shots blocked in quick succession with the visitors fighting for an equaliser with the game still in the balance.
They went desperately close with 20 minutes remaining when Ambrose's shot came back off the post, and Tamas Kadar managed to get a block on Danns' follow-up.
But Ranger made sure deep into stoppage time when he ran clear from Routledge's pass and beat Julian Speroni with ease.