Both teams went into Friday night's game at Carrington Park knowing a win would at least temporarily lift them to fourth before the other fixtures on the weekend.
The Jets had eight more shots and four more attempts on target but wasteful finishing and some good saves from Wanderers goalkeeper Kaylie Ann Collins kept them to a single goal.
Newcastle struck first in the 14th minute when Libby Kopus-Brown drilled in a strong right foot shot from just outside the area following a lay-off from former Wanderer Sarina Bolden.
The Wanderers equalised in the 43rd minute when Sophie Harding finished in classy fashion after running onto a  Holly Caspers flick from a long goal kick.
Western Sydney's 79th minute winner was slotted in from close range by Vicky Bruce, after a 25-metre free-kick from captain Amy Harrison was pushed into her path by Jets goalkeeper Isobel Nino.
Newcastle could have been well clear by halftime, but squandered several opportunities prior to Harding's equaliser, which extended her Wanderers club record for goals in a season to nine.
Philippines star Bolden was a constant threat to her old club, but the one blot on her energetic performance was her failure to convert several attempts, which were either saved or off target.
Coming off back-to back losses, the Wanderers enjoyed a slight edge in possession and forced a couple of early corners in front of a crowd of 3,873 in the NSW Central Tablelands venue.
The Jets remained eighth on the ladder after a third loss in their past four games.
Harrison celebrated a win on her 100th ALW appearance and it was a triumphant homecoming for the Wanderers' Bathurst product Cushla Rue.
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