PAUL Scharner's 72nd-minute winner earned Albion a club-record fourth Barclays Premier League away win of the season as the brilliant Baggies twice came from behind at the Stadium of Light.
After Nicky Shorey had opened the scoring with a tenth-minute own goal, Peter Odemwingie levelled on 29 with his 11th of the season, only for Phil Bardsley to restore the Black Cats' lead two minutes later.
But Roy Hodgson's men totally bossed the second half and Youssouf Mulumbu's fifth of the season on 54 deservedly clawed them level - before Scharner decided it.
Hodgson's men were full value for their tenth win of the campaign as they stretched their unbeaten Premier League run to a club-record seven games.
Sunderland started the day just one place and two points better off than 13th-placed Albion, who were boosted before kick-off by the news second-bottom Wolves had lost 3-0 at home to Everton in the day's early kick-off.
Hodgson named an unchanged side for the long trip to Wearside, although there were two changes on the bench, with fit-again duo James Morrison and Gabriel Tamas replacing Gianni Zuiverloon and Pablo Ibanez.
The Baggies were roared on from the first whistle by a huge following support, which was swelled by the club making their annual gesture of providing free coach travel for around 2,000 fans as a thank you for their loyal support.
Albion started confidently and recorded the first shot of the game when, in the third minute, Scharner chested down a Sunderland clearance 20 yards out and fired wide.
On 6, John Mensah's poor headed clearance flew straight to Simon Cox, who drilled over from an acute angle.
But it was the hosts who broke the deadlock in the tenth minute.
Asamoah Gyan swung in a cross from the left and Shorey, under pressure from Ahmed Elmohamady, unwittingly planted an unstoppable header past Scott Carson.
The Mackems immediately suffered an injury setback, with Mensah limping off and being replaced by Anton Ferdinand.
It was Sunderland's first goal for five games and they went close again on 13 when Gyan fired into the side-netting after turning sharply from Elmohamady's centre.
Albion gradually began to peg back the Black Cats again but with home skipper Lee Cattermole tigerish in the tackle, they struggled for openings.
Back came Sunderland and the visitors were relieved to see the unmarked Michael Turner fail to connect at the back post with Steed Malbranque's in-swinging free-kick, which had been flicked on by Bardsley.
But Albion were level on 29.
Jonas Olsson, who had remained in the Sunderland penalty area after going up to attack an Albion free-kick, headed Jerome Thomas' deflected centre goalwards and Odemwingie smashed home from close range.
But the Baggies' joy was short-lived
Just two minutes later, former Albion loan signing Kieran Richardson tapped a 30-yard free-kick sideways to Bardsley who gave Carson no chance with a right-foot rocket which flew into his top-right corner after taking a deflection off Odemwingie.
Although Albion continued to enjoy plenty of possession in the opposition half, they failed to record another effort at goal until two minutes into stoppage time, when Simon Mignolet stooped to gather Chris Brunt's 30-yard free-kick in front of his left-hand post.
Steve Bruce made another change at half-time, with Bolo Zenden coming on for Richardson.
It was Sunderland who threatened first after the restart, with Cattermole seeing a ferocious 20-yard strike blocked in the box after Albion had only half-cleared a Malbranque corner.
Albion created a half chance of their own on 51 when Odemwingie found Brunt in space on the edge of the box, only for his deflected shot to sail straight into Mignolet's arms.
With Sunderland getting plenty of men behind the ball, Albion had to move the ball around patiently - and one such move brought them level on 54.
A neat spell of keep-ball resulted in Mulumbu feeding Odemwingie before he charged into the box to collect the Nigerian's return ball and poking inside the far post with the aid of a deflection off Turner.
Albion were now oozing confidence but, two minutes later, Odemwingie could only shoot straight at Mignolet from 20 yards.
On 62, Bardsley denied Cox a certain goal with a last-ditch near-post lunge which cut out Odemwingie's low cross after the former Lille ace had broken clear down the left.
It was all Albion now and, moments later, Brunt fired just over from 25 yards.
They went even closer on 69, with Mignolet having to pull off the save of the game to keep out Olsson's downward header from Brunt's in-swinging free-kick.
A Baggies goal had been coming - and it duly arrived in the 72nd minute.
Steven Reid slipped through Odemwingie and the striker pulled the ball across goal for Scharner, who found the bottom right-hand corner with a first-time shot from 12 yards.
Albion remained on top and Mignolet had to pull off a smart near post save to deny Cox on 76.
Sunderland finally built up a head of steam in the closing stages and sub Marc-Antoine Fortune and the once-again impressive Abdoulaye Meite combined to divert Danny Welbeck's header over from Malbranque's corner.
Then, three minutes into stoppage time, Welbeck raced onto Gyan's flick-on but his attempted lob sailed over.
That was Albion's final scare and Peter Walton's final whistle sparked a mass celebration in the away end.
SUNDERLAND (4-4-2): Mignolet; Onuoha, Turner, Mensah (Ferdinand 11, Sessegnon 78), Bardsley; Elmohamady, Cattermole (c), Richardson (Zenden HT), Malbranque; Gyan, Welbeck. Subs not used: Gordon (gk), Henderson, Muntari, Colback.
ALBION (4-4-2): Carson; Reid, Meite, Olsson, Shorey; Brunt (c) (Morrison 78), Mulumbu, Scharner, Thomas; Odemwingie (Tamas 90+2), Cox (Fortune 85). Subs not used: Myhill (gk), Vela, Cech, Jara.
GOALS: SUNDERLAND - Shorey (own goal, 10), Bardsley (31). ALBION - Odemwingie (29), Mulumbu (54), Scharner (72).
BOOKINGS: SUNDERLAND - Richardson (dissent 25), Cattermole (foul 45+4). ALBION - Tamas (foul 90+4).
REFEREE: P Walton (Northamptonshire)
ALBION STARMAN: Paul Scharner.
PIC: WEARSIDE WONDER...Scharner celebrates his match-winning strike
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