Derby County produced a superb display of attacking football to dispose of fellow high-flyers West Bromwich Albion on Wednesday night.
The Rams barely put a foot wrong as they made the Baggies look distinctly average, although the hosts did themselves no favours in a very disjointed display.
The scene was set with a gift of an opening goal that West Brom never recovered from, the Rams turning the screw in style to score twice in each half and move to within two points of new league leaders Leeds United.
If any kind of statement needed to be sent out to the rest of the Championship, this was the night to do it against a side full of Premier League standard players and themselves in the top three before kick-off. What transpired was a confident and composed display from the visitors who never looked in any danger.
Jay Rodriguez drove a low shot just wide seven minutes in as the Baggies threatened earliest, but the Baggies man would be the man to set up Derby's opener moments later.
His attempted back pass to Sam Johnstone from 40 yards out went straight into the path of Jack Marriott who was able to fire low past the keeper and put the Rams in front with their first chance of the game.
Their second came five minutes later and with it another goal. The Rams were allowed too much time to pass their way into the penalty area via Harry Wilson and Mason Mount, before Tom Lawrence collected the ball and fired low into the net via the far post with a lovely finish.
Another good break forward then saw Mount's shot blocked by a defender as the Baggies were again asked questions defensively, Marriott then shooting straight at Johnstone from a Mount lay-off on 27 minutes. The home fans were becoming very impatient with their side.
Three quick chances then came the Rams' way as a good move from right to left ended with Scott Malone's low shot being blocked by Johnstone's legs and Lawrence's follow up going just wide via a deflection. From the corner, Tom Huddlestone's low volley was again blocked by the Baggies keeper and the defence finally cleared their lines.
An error by Richard Keogh gave Rodriguez a chance to create something but he instead passed straight into Carson's hands, before he did a little better with a low shot the Rams keeper parried away well.
West Brom then felt they should have had a penalty as Dwight Gayle seemed to be tripped by Malone on his way to goal but nothing wass given. Replays firmly placed it in the 'seen them given' category.
Half-time saw the Baggies make two changes but Derby still threatened first, Wilson shooting just wide after a good break forward by Fikayo Tomori.
Harvey Barnes then twice saw efforts go close, one just wide and another saved low by Carson, before the Rams got a crucial third goal.
The ball found Wilson 25 yards out who took a touch before arrowing a low shot low into the corner past a statuesque Johnstone who had no chance once again.
Barnes was West Brom's biggest threat and he curled an effort inches wide of the post on the hour mark as the hosts desperately sought a way back into the game, Sam Field doing similar after cutting in from the right on 67 minutes.
But it would be the Rams who would register again four minutes later and it was Malone who got it. The left-back had been a good attacking threat throughout and when he was gifted the ball inside the Rams' half, he sent sub Mason Bennett away and was on hand in the penalty area to receive the ball back and finish low past Johnstone to end the game as a contest.
The Baggies did get one back with eight minutes to go as Barnes slipped the ball through to Rodriguez who in turn finished low past Carson.
Bennett then got free at the other end but fired too high when in a good position, while Barnes shot low at Carson as the hosts chased another goal to reduce the arrears further, but 4-1 was how it would stay as the Rams fans toasted a superb away performance.
West Brom: Johnstone, Gibbs (Mears 46), Bartley, Phillips (Morrison 62), Brunt (c), Barnes, Gayle (Robson-Kanu 46), Rodriguez, Adarabioyo, Dawson, Field
Subs not used: Myhill, Sako, Edwards, Hoolahan.
Derby: Carson, Tomori, Keogh (c), Wilson, Mount, Waghorn (Nugent 73), Lawrence, Marriott (Bennett 67), Bogle, Huddlestone, Malone (Forsyth 81).
Subs not used: Roos, Johnson, Holmes, Davies.
Ref: Robert Jones