Valerien Ismael's new direct approach at West Brom blew away shell-shocked Sheffield United who conceded three set pieces.
Both these clubs were relegated last term but only Albion have a decent chance of bouncing straight back up on this evidence.
The visitors were without England keeper Aaron Ramsdale who is set to join Arsenal after a fee in excess of £20million was agreed.
His replacement, the Dutch keeper Michael Verrips, made his League debut and had a baptism of fire under siege from long throws and corners.
He and United were found desperately wanting under the bombardment as Jack Robinson headed into his own net before second half goals from Dara O'Shea, Alex Mowatt and Callum Robinson ruthlessly sent them packing.
Verrips had to pick the ball out of the net twice in the first 15 minutes but former Blade Robinson was ruled offside on both occasions.
A bad night for Slavisa Jokanovic ( Image:
PA)
Albion took the lead in the 26th minute when Jack Robinson headed into his own net from Darnell Furlong's long throw.
United almost equalised swiftly as Billy Sharp released David McGoldrick down the middle. But the veteran striker rolled a low right-foot finish past the post with a poor finish when clean through.
Albion had further chances to extend their lead but Alex Mowatt shot over from distance.
Mowatt was involved after the break when the Baggies quickly doubled their advantage as they seized control. Verrips couldn't hold the midfielder's 47th-minute corner as he had two touches but failed to gather the ball. It fell for defender O'Shea who toe-poked in which left United boss Jokanovic shaking his head on the touchline.
A huge win for the Baggies ( Image:
PA)
Albion made it 3-0 six minutes later when Karlan Grant played in Mowatt who found the back of the net with his first goal for the club from a low right-foot finish. It was the hosts' first goal from open play as their biggest threat was at set-pieces
Full-back Furlong hurled in another long throw from the right which led to the fourth as Kyle Bartley beat Verrips to it before Robinson helped it over the line in the 59th minute.
It was in-form Robinson's third goal in as many games for Albion this term.
While Furlong might have got on the scoresheet himself had he not blazed Conor Townsend's cross over.
The sorry visitors took until the 72nd minute to test Sam Johnstone when he had to dive to his left to push away John Egan's header.
On Ramsdale's impending exit, Jokanovic said post-game: "It's not really what I want but it's difficult to stop this kind of situation. It's a huge deal for the club."