Jayson Molumby netted an incredible stoppage time winner as Albion beat Sheffield Wednesday 2-1 at The Hawthorns on Saturday afternoon.
Adam Armstrong’s debut goal gave the Baggies a deserved lead, but the visitors pegged them back late via Callum Paterson.
Midfielder Molumby’s flick in the 96th minute sparked chaos and jubilation, though, and handed Tony Mowbray’s men three massive points.
The result extends their unbeaten run to 11 matches, and - even if just temporarily - lifts them to fifth.
The boss stuck Armstrong in from the start, and also put Isaac Price into his XI alongside Karlan Grant and Kyle Bartley.
The hosts began brightly yet didn’t threaten properly until Torbjorn Heggem saw a header saved, with Albion’s new No.32 smashing the rebound off the post.
Grant and Armstrong both struck off-target, while goalkeeper Joe Wildsmith - in following Alex Palmer’s deadline day departure - needed to smartly keep out Djeidi Gassama’s effort down the other end.
Despite those openings the game was goalless at the break, though the action continued straight after the interval.
Grady Diangana had a golden opportunity bravely blocked almost immediately before the Baggies hit the woodwork again through a mix of Molumby’s cross and a Wednesday defender’s foot.
The visitors then put the ball in the net soon after, only for it to be disallowed when the assistant referee flagged offside.
Both Albion and the Owls continued creating half-chances, but the game’s first goal arrived 16 minutes from the finish - and you would win no prizes for guessing who netted it.
Substitutes Will Lankshear and Tom Fellows combined brilliantly to set up Armstrong inside the area, and he delicately tapped home a maiden goal in blue and white.
Fellow play-off chasers Wednesday thought they had stolen a draw in the early stages of added time, Paterson scrambling a late equaliser.
However, Molumby was on hand to flick past James Beadle in the dying seconds and secure the victory, bringing wild celebrations around The Hawthorns.
Albion: Wildsmith; Furlong, Bartley, Heggem, Styles; Molumby, Mowatt (Diakite 80); Diangana (Fellows 67), Price (Lankshear), Grant (Johnston 67); Armstrong (Wallace 80).
Substitutes: Griffiths, Frabotta, Swift, Cole.
Attendance: 25,452 (2,515).