Taylor struck with a terrific free-kick from just outside the area after Alan Smith was penalised for a tackle on Michael Brown.
Dutch star Denny Landzaat provided the dummy before Taylor hammered a shot into the right-hand corner beyond the reach of Shay Given.
Earlier ex-Newcastle defender Titus Bramble was the Latics' hero with a superb goal-line clearance to deny Mark Viduka.
Wigan survived an early scare when French striker Antoine Sibierski went down heavily under a double challenge but recovered after treatment.
The Latics had the first shot of the match when Paul Scharner made a raid from the back and tried his luck from long range. His effort took a deflection off Geremi but Given had it covered, getting down on his knees to keep it out.
Sibierski was soon involved in the action again against his old team, going down in the box under pressure from Steven Taylor but ref Mike Dean was well-positioned and not swayed by the home fans' claims a penalty.
Wigan threatened again when Brown won possession from James Milner and launched himself up the left wing. The ball into the box was a good one but the Latics' strike-force was nowhere to be seen.
Newcastle had shown little attack-wise in a disappointing first half but they had a real opportunity when Kevin Kilbane was penalised for a foul on Milner five yards outside the box. It was tailor-made by Emre but he failed to beat the wall.
The Magpies produced the first real goal threat of the match soon after the re-start but Bramble - who has some unhappy memories from his time at St James' Park - cleared from Viduka following a mix-up between Chris Kirkland and Mario Melchiot.
But Wigan took the lead after 65 minutes when Taylor came up with a precious goal with a shot that found its way past a five-man wall to beat Given with a free-kick into the right corner.
Newcastle keeper Given enjoyed a real stroke of good fortune as Wigan hunted the killer goal.
Under pressure from Marcus Bent, he somehow hooked the attempted clearance over his shoulder, and was lucky only to concede a corner, and in the last minute Julius Aghahowa hammered into the side-netting.