Paraguayan Almiron played in Bruno Guimaraes's pass in the 32nd minute and curled a left-footer into the top corner of the net for his first goal of the season.
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Newcastle were in charge throughout against a Palace side who appeared to be suffering a hangover from Sunday's FA Cup semi-final defeat and rarely threatened the home goal.
The hosts were unable to add to Almiron's cracker but the mood at St James' Park was buoyant throughout as the home side moved to within goal difference of the top half of the table.
When Howe took charge in November, Newcastle were 19th in the table after 11 games, five points from the safety zone. Incredibly they have now reached 40 points -- the old benchmark for safety -- with five games to spare.
"The players have ran themselves into the ground in the last couple of weeks. There is work to do defensively but they have been much improved. Tonight showed that," Howe said.
Howe spoke of turning St James' Park into a fortress when he was hired and Wednesday's win was Newcastle's sixth in succession at home in the league -- something they had not achieved in the top flight since the 2003-04 season.
Right from the start they were in top gear and the only surprise was that they did not take the lead earlier.
Zaha also curled narrowly over in stoppage time but an equaliser would have been harsh on Newcastle.
While Newcastle are up to 11th, Palace dropped to 14th with 37 points.