SUPER-SUB Craig Beattie's late stunner saw injury-ravaged Albion defy all the odds to record an impressive Walkers Stadium victory and move within one point of leaders Watford.
The Baggies went into the early kick-off against the Foxes without NINE first-team regulars.
But Albion belied their injury and suspenion troubles from the first whistle and Zoltan Gera deservedly fired them into a 32nd-minute lead with his first league goal of the season.
Only a controversial Ian Hume equaliser 15 minutes from time looked like denying Tony Mowbray's men all three points.
But Scotland international Beattie stepped off the bench to score his first goal in three months with a sublime right-foot curler two minutes from time to extend the Baggies' unbeaten run on the road to five games.
Albion headed to Leicester minus suspended duo Bostjan Cesar and Paul Robinson and the sidelined Dean Kiely (broken toe), Carl Hoefkens (hamstring), Kevin Phillps, Ishmael Miller, James Morrison, Martin Albrechtsen and Neil Clement (all knee).
In their absence, Luke Steele was handed his Albion debut, Jared Hodgkiss and Shelton Martis made their full league debuts and Pele was granted his first Championship start in four months in a makeshift defence.
Albion started brightly and, in the seventh minute, Chris Brunt spotted Hodgkiss' marauding run down the left.
The young full-back powered into the box and the hosts needed Patrick Kisnorbo's last-ditch block to prevent Roman Bednar getting on the end of his cross.
Two minutes later, Filipe Teixeira intercepted Stephen Clemence's pass and broke forward swiftly.
Bednar was crying out for a throughball but the Portuguese ace only had eyes for goal and ended up being dispossessed by Gareth McAuley on the edge of the area.
Robert Koren fed Gera down the right in the 12th minute and Kisnorbo could only deflect the Hungarian's cross, allowing Bednar to get in a reaction header, which went just wide of the near post.
City threatened for the first time in the 22nd minute and were denied what looked a certain goal when Richard Stearman broke down the right.
The full-back's low centre slid all the way through to Carl Cort whose shot was superbly blocked by Leon Barnett.
But the Baggies stormed into a 32nd-minute lead when Brunt latched onto Jonathan Greening's diagonal ball and turned Stearman inside out before delivering a pinpoint cross for Gera to head home at the back post.
A minute later, 'Magic Magyar' Gera was in the action again when his cross from the right was deflected across the six-yard box and flashed inches ahead of Bednar's out-stretched leg.
Barnett headed the resulting Brunt corner back across goal - but Martis was denied by Cort's vital headed clearance.
The Foxes threatened from a Clemence free-kick in the 36th minute when Stearman headed the ball towards Kisnorbo who nodded over when he should at least have hit the target from ten yards.
Leicester were forced into a change in the 41st minute when James Wesolowski limped off and was replaced by Andy King.
Keeper Steele produced a wonder save a minute before the break when he plunged to his left to somehow tip over Kisnorbo's downward header from another Clemence free-kick and hand the Baggies a half-time lead.
Albion started the second-half brightly and Greening's quick feet saw him jink inside Kisnorbo and McAuley before curling a right-footed shot just over.
Martis almost got on the end of Brunt's free-kick on the hour-mark but Kenton managed to scramble the ball away.
Albion continued to press for a second goal and Koren reacted quickest to pounce on the loose ball and saw his shot deflect off Stearman and just over.
Gera made a darting run three minutes later and threaded the ball through to Bednar, who controlled well but could not get his shot away under pressure from McAuley.
Then, in the 69th minute, Martis' low, right-wing cross flicked up off Kisnorbo and deflected off Bednar's chest into the side-netting.
Teixeira left Stearman and Kenton for dead on the left-hand touchline before driving into the penalty area and firing just wide of the far post, when he had team-mates better placed to shoot.
But all of Albion's hard work came undone in the 75th minute - in controversial circumstances.
A huge punt from Foxes keeper Martin Fulop bounced all the way through to Steele, who appeared to be clattered by pint-sized striker Hume.
After the two had clashed, the ball dropped into the net and referee Mick Russell waved away Albion's appeals for a foul.
Albion came under further pressure when Barnett gave the ball away cheaply in the final minutes.
Sub Jonathan Hayes ran at the Baggies defence and Steele did well to gather his stinging drive at the second attempt.
But Albion weren't to be denied a fully deserved fourth away win in five games.
Substitute Beattie ran onto the commanding Pele's sublime defence-splitting ball in the 88th minute.
The Scotland international jinked inside McAuley before curling a delicious shot into the far corner from just inside the area - to send Albion's huge 3,000-plus support into raptures.
Mowbray's men comfortably ran down the clock to keep a stranglehold on second place.
LEICESTER (4-3-3): Fulop; Stearman, Kisnorbo, McAuley, Mattock; Kenton, Wesolowski (King 41), Clemence; A Chambers (Hayes 60), Cort, Hume. Subs not used: N'Gotty, Sheehan, Odhiambo.
ALBION (4-4-1-1): Steele; Martis, Barnett, Pele, Hodgkiss; Gera, Koren (Chaplow 79), Greening, Brunt; Teixeira; Bednar (Beattie 73). Subs not used: MacDonald, Tininho, Worrall.
GOALS: LEICESTER - Hume (75). ALBION - Gera (32), Beattie (88).
BOOKINGS: ALBION - Martis (foul 78).
REFEREE: M Russell (Hertfordshire).
ATTENDANCE: 22,088.
ALBION STARMAN: Pele.
PIC: YOU BEATTIE...Craig curls home his 88th-minute stunner
See Tony Mowbray and Shelton Martis' post-match interviews NOW on Albion TV as part of a 99p seven-day trial. To subscribe, click here.
