Albion registered a five-star performance to see off Swansea City 5-1 at The Hawthorns to secure a sixth successive victory for the first time since 2004.
Matheus Pereira put in a superb man-of-the-match display to orchestrate the impressive five-goal triumph, scoring his fifth goal of the season and claiming three assists in the process - coming against a Swans side previously unbeaten on their travels this term.
Semi Ajayi put the Baggies on their way when he nodded home from close range in the 25th minute before Pereira added a second with a well-taken finish.
Sam Surridge pulled one back for the Swans only for Hal Robson-Kanu to latch on to Pereira's throughball and register his sixth goal in nine matches to make it 3-1 at the interval.
And the on-loan Brazilian was at it again after the restart as he set up further goals for Matt Phillips and Kyle Edwards to seal a memorable afternoon for Slaven Bilić's side.
In-form Albion, unbeaten in 10 at the top of the Sky Bet Championship, have now recorded 16 league matches without defeat on home soil stretching back to February, the club's longest run since 1920.
With the hosts unchanged for a third successive match, an open start to proceedings saw half-chances at either end inside the opening 15 minutes, Surridge going closest when his drilled effort was parried by Sam Johnstone.
Baggies skipper Jake Livermore saw his long-range strike tipped over by Swansea stopper Freddie Woodman before Kyle Bartley enjoyed the clearest chance of the opening quarter in the 22nd minute.
Phillips sent over a deep free-kick and the unmarked Albion centre-back's header was kept out by the feet of Woodman, who managed to pounce on the rebound.
Yet the hosts were not to be denied three minutes later.
Phillips did well to chase down a hopeful ball and win a corner, which Pereira swung to the back post and Bartley was on hand to header back across goal for Ajayi to nod home from close range.
And it was 2-0 in the 34th minute courtesy of a flowing team move which saw Pereira work space with a great piece of skill before going on to superbly finish Kieran Gibbs' low cross from 12 yards.
Surridge reduced the arrears with a close-range finish from Matt Grimes' corner, only for Robson-Kanu to restore Albion's two-goal advantage just before the break having been sent clean through by Pereira's sumptuous throughball.
The Baggies lost Kieran Gibbs to injury in the 56th minute, replaced by Darnell Furlong.
And the visitors were indebted to keeper Woodman as he saved from defender Kyle Naughton with Albion pressing for a fourth goal.
Bartley was next to leave the field as he sustained a facial injury, yet it wasn't long before Albion made sure of all three points with two goals in four minutes - Pereira again the creator.
The playmaker sent over an inch-perfect cross for Phillips to head home from six yards before capping off a sweeping move by sending the final touch into the path of substitute Edwards for the youngster to convert.
Albion: Johnstone, Ferguson, Bartley (Hegazi 66), Ajayi, Gibbs (Furlong 56), Livermore (c), Sawyers, Phillips, Pereira, Diangana (Edwards 71), Robson-Kanu.
Subs: Bond, Barry, Krovinović, Austin.