PAUL Scharner's late winner earned Albion their first league win at Newcastle in more than 34 years.
The Austrian international struck in the 85th minute after the Baggies had twice conceded the lead.
In a pulsating contest, Peter Odemwingie, fresh from his late winner at Blackburn on Saturday, fired Roy Hodgson's men ahead in the 20th minute with his fourth of the season.
Demba Ba levelled with his 12th of the term 14 minutes later before summer signing Gareth McAuley's first Albion goal a minute before the break restored the visitors' lead.
Ba looked to have rescued Alan Pardew's side a point when he equalised nine minutes from time - but Scharner's second of the season four minutes later earned Albion an impressive fourth away win.
Hodgson made one enforced change with injured North East native James Morrison being replaced by Jerome Thomas.
George Thorne and Marc-Antoine Fortune, recalled yesterday from loan spells with Championship outfits Portsmouth and Doncaster respectively, were named among the subs.
Pardew also made one enforced change as Haris Vuckic came in for the suspended Yohan Cabaye.
Newcastle, one of this season's success stories, started the day in seventh spot - some nine points and six positions better off than the Baggies.
The hosts recorded the first effort at goal, with Leon Best back-heading Vuckic's inswinging free-kick high over the bar in the third minute.
But that seemingly harmless incident prompted Albion's first setback of the evening.
As Steven Reid contested the header with Best, he landed awkwardly and although he tried to soldier on, the right-back had to be replaced by Billy Jones in the seventh minute.
Reid was in possession when he collapsed to the ground and was robbed by Jonas Gutierrez, but the Argentina winger sportingly put the ball into touch despite being in a promising position,
Jones was soon in the thick of the action and there was a moment of panic when his clearance cannoned off Best and bounced into the Baggies box. However, the impressive Ben Foster was alert to the danger and smothered the ball before Ba could pounce.
Albion gradually got a foothold in the game and worked the ball into a couple of dangerous positions for Odemwingie in quick succession - but they came to naught.
Despite his inactivity, Foster showed again in the 18th minute that he was very much on his toes when he raced off his line to prevent Ba getting on the end of Vuckic's defence-splitting pass.
However, it was Albion who drew first blood when they turned defence into attack to deadly effect in the 20th minute.
Nicky Shorey intercepted the ball deep in the Albion half and found Brunt, who sent Odemwingie scampering clear with a sublime throughball. The Nigeria striker advanced to the edge of the Toon box before calmly stroking the ball past Tim Krul and in off the left-hand post.
Just two minutes later, Ba had the ball in the Albion net but the home fans' goal joy was correctly nipped in the bud by an offside flag, with strike partner Best the offender.
But the Baggies were now playing with real freedom and it was United keeper Krul who was next called into action, comfortably catching Shane Long's looping header after Jonas Olsson had nodded Brunt's free-kick across the Toon box.
Moments later, the Dutch custodian had to be at full stretch to tip away Brunt's vicious centre, thus denying Long a simple header.
Albion were asking all the questions and, after Thomas raced clear down the right, Krul came to Newcastle's rescue again when he cut out the winger's low cross, with Long lurking behind.
But it was 1-1 in the 34th minute. Gabriel Obertan was allowed to carry the ball a long way before being upended by Thomas on the edge of the Albion box.
Foster managed to get a hand to Ba's curling free-kick but could only help the ball on its way into his top left-hand corner.
The game's momentum swung Newcastle's way after the equaliser.
But the Baggies saw off their mini spell of pressure and regained the initiative.
And they were deservedly back in front a minute before the break.
From Brunt's deep free-kick, Scharner rose highest at the back post to direct the ball to the unmarked McAuley who had the simple task of nodding past Krul from six yards.
The Baggies made it into the break with their lead intact - but only just.
In the first minute of stoppage time, Vuckic rattled the underside of the Albion bar with a stunning 25-yard strike.
The rebound bounced awkwardly to Ba who was unable to direct his header towards the open net.
Newcastle were the first to threaten from the restart and after McAuley directed his attempted clearance from Gutierrez's cross straight to Vuckic, Scharner saved Albion's bacon by dispossessing the Toon midfielder inside the Albion box.
However, Scharner went from hero to villain moments later when he gave the ball away to Ryan Taylor. Ba surged forward before curling just wide from 20 yards.
Brunt was having a terrific game on the left but could only shoot tamely wide from distance on 51.
Two minutes later, the woodwork denied Albion a 3-1 lead.
Long raced onto Youssouf Mulumbu's though-pass before rounding Krul and lifting the ball over the recovering James Perch, only to see his effort smash the frame of the open net.
Albion regained possession and Mulumbu also had his head in his hands when he saw his goalbound shot from Odemwingie's centre blocked in a crowded goalmouth.
After their lucky escape, Newcastle broke upfield but Foster easily gathered Best's grass-cutter from just outside the box.
Albion looked full of threat every time they poured forward and Toon skipper Fabricio Coloccini protected Krul's goal when he diverted Odemwingie's acute drive wide.
However, Newcastle steadily began to exert pressure on the Albion goal and Odemwingie did well to read the Toon's short corner and deflect wide Cheick Tiote's 20-yard shot.
Moments later, sub Hatem Ben Arfa jinked past two Baggies players before smashing a long-range effort into McAuley.
When Albion only half-cleared a Danny Simpson centre, Ben Arfa nodded the ball to Obertan who shot well over from 18 yards.
The Baggies were struggling to get out of their own half and Vuckic was the next to try his luck, firing just wide from the edge of the area.
But the visitors earned some respite and, in the 74th minute, Brunt curled a delicious 25-yard effort narrowly past the far post.
Krul kept his team in it in the 80th minute when he blocked Long's acute drive after the Ireland international had skipped past Colocinni.
But, just a minute later, it was 2-2.
Ba exchanged a clever one-two with Ben Arfa before blasting an unstoppable shot past Foster from the edge of the box.
Newcastle were now pressing for a winner and Foster had to produce a wonderful one-handed save to push over Vuckic's 30-yard missile.
But, just five minutes from time, there was to be one more dramatic twist.
Scharner poked Albion back in front from ten yards from Odemwingie's tee-up after great play by Long down the right.
And Foster ensured Albion kept their noses in front when he produced a fine reflex save to deny Tiote from sub Ryan Taylor's corner.
NEWCASTLE (4-4-2): Krul; Simpson, Perch, Coloccini (c), Santon (R Taylor HT); Obertan (Shola Ameobi 72), Vuckic, Tiote, Gutierrez; Best (Ben Arfa 61), Ba. Subs not used: Elliot (gk), Williamson, Abeid, Sammy Ameobi.
ALBION (4-4-2): Foster; Reid (Jones 7), McAuley, Olsson, Shorey; Thomas (Dorrans 69), Scharner, Mulumbu (Thorne 76), Brunt (c); Long, Odemwingie. Subs not used: Fulop (gk), Fortune, Dawson, Cox.
GOALS: NEWCASTLE - Ba (34 & 81). ALBION - Odemwingie (20), McAuley (44), Scharner (85).
BOOKINGS: NEWCASTLE - Colocini (foul 89).
REFEREE: A Taylor (Manchester).
ATTENDANCE: 51,060 (800 away fans).
ALBION STARMAN: Chris Brunt.