Albion triumphed 4-1 over Bristol City to record a fourth successive league victory for the first time since 2012.
The in-form Baggies, who went into the encounter on the back of wins over Stoke City, Hull City and Sheffield Wednesday, are now unbeaten in eight Sky Bet Championship matches.
Kieran Gibbs put Albion on their way after just 10 minutes, slotting home a superb backheel from the impressive Grady Diangana, who shone at The Hawthorns alongside the scintillating Matheus Pereira in what was a fantastic team performance.
And it was the Portuguese who added an exquisite second just before half-time when he clipped a deft free-kick into the top corner to put Slaven Bilić's side firmly in control.
Robins substitute Famara Diedhiou reduced the arrears late on but Hal Robson-Kanu replied almost immediately with his fifth goal in seven matches before Charlie Austin came off the bench to bag his second in as many games and seal all three points.
Victory, coming against a City side who had previously tasted just one defeat on the road this term, extends Albion's unbeaten home league record since February and ensures they regain top spot in the table.
Head coach Bilić made four changes from Saturday's dramatic victory over Sheffield Wednesday, fit-again Gibbs returning alongside Nathan Ferguson, Romaine Sawyers and captain Jake Livermore, all of whom had completed suspensions.
And it took the hosts just 10 minutes to open the scoring courtesy of a touch of brilliance from Diangana.
The winger won possession in a dangerous area and surged forward, racing on to a throughball from Robson-Kanu before showing fantastic awareness to backheel into the path of Gibbs, who slotted into an almost empty net.
Diangana came close to getting in on the act himself moments later, firing narrowly wide.
Yet Pereira did add a sublime second in the 40th minute as he dinked an inch-perfect free-kick over the wall and into the top corner from the edge of the penalty area.
Diangana and Gibbs both drilled efforts goalwards as Albion surged forwards in search of further reward yet it remained 2-0 at the interval.
City flew out of the blocks at the start of the second half but the Baggies stood up to the pressure and went close to a adding a third themselves through Robson-Kanu.
Diangana was denied by a last-ditch challenge from Robins centre-back Nathan Baker soon after the hour mark, before a combination of Ferguson and Kyle Bartley almost put through their own net at the other end.
An end-to-end second half then saw Robson-Kanu denied by City goalkeeper Daniel Bentley.
Robins substitute Diedhiou pulled back a goal for the visitors in the 80th minute but it did not prevent Albion from sealing all three points as Robson-Kanu converted just two minutes later to restore the home side's two-goal advantage.
Baggies sub Austin then got in on the act in the 87th minute, firing home from close range after his initial effort had rebounded of a post, to put the gloss on a fantastic display and ensure the Baggies remain unbaten on home soil against the Robins since 1993.
Albion: Johnstone, Ferguson, Bartley, Ajayi, Gibbs (Furlong 70), Livermore, Sawyers, Phillips, Pereira (Austin 83), Diangana (Edwards 76), Robson-Kanu.
Subs: Bond, Hegazi, Barry, Krovinović.