Albion claimed the derby spoils at Aston Villa as they celebrated a 2-0 victory courtesy of two goals in the space of four first-half minutes.
Fit-again Hal Robson-Kanu sent a looping header over Lovre Kalinic in the 41st minute before Jay Rodriguez added a quickfire second off a post from long range, his 17th goal of the season, to settle an enthralling encounter at Villa Park.
It sent the 2,167 Baggies fans present, as well as the 2,500 watching on big screens back at The Hawthorns, into raptures.
It was Albion's first trip across the midlands to face their neighbours since securing all three points in 2015, ensuring back-to-back away triumphs at Villa.
Victory means Albion have now won seven of their last eight away matches in the Sky Bet Championship, keeping four successive clean sheets on the road in all competitions.
Darren Moore made three changes from the midweek draw against Nottingham Forest, Robson-Kanu and Ahmed Hegazi returning from injury alongside captain Gareth Barry.
Mason Holgate was denied by a last-ditch Tommy Elphick challenge after just four minutes, yet Albion were indebted to Sam Johnstone shortly afterwards for a crucial point-blank save to deny Tammy Abraham from 12 yards.
Kalinic was alert to parry Jacob Murphy's curling long-range effort as the encounter flowed from end to end amid a pulsating 39,263 atmosphere.
Murphy shot straight at Kalinic when played through down the left channel in the 23rd minute, before being thwarted by Tyrone Mings' challenge when sent into a similar position just after the half-hour mark.
Yet the Baggies finally made the breakthrough in the 41st minute.
Holgate delivered an inch-perfect cross from the right which was met by Robson-Kanu, who sent a looping header over Kalinic.
And the visiting faithful were in dreamland just four minutes later.
Rodriguez pounced on possession in a promising central area, surged forward and drilled home a 20-yard strike off the inside of a post.
Sam Field replaced goalscorer Robson-Kanu at the interval, with Harper taking a central attacking role, while Villa were forced to introduce goalkeeper Jed Steer in place of the injured Kalinic.
Jake Livermore headed off the line early in the second period as an open encounter continued after the break, albeit with the Baggies largely looking to soak up pressure and looking to hit the hosts on the counter-attack.
Moore introduced Kyle Bartley in place of Murphy in the 78th minute, with Johnstone called upon to make a smart save from John McGinn as openings became few and far between and the mature visitors excellently managed their two-goal advantage.
Mings headed wide for the home side before Barry, who spent over a decade with Villa, was handed a rousing reception by all supporters when replaced late on.
Yet it was the Baggies supporters celebrating at the final whistle.
Albion: Johnstone, Holgate, Dawson, Hegazi, Gibbs, Harper, Barry (c) (Johansen 86), Livermore, Robson-Kanu (Field 46), Rodriguez, Murphy (Bartley 78).
Subs: Bond, Adarabioyo, Montero, Hoolahan.