West Brom reclaimed the leadership of the Championship with an emphatic dismantling of Swansea's unbeaten away record.
Something had to give if Slaven Bilic's team were to return to the top at the expense of Leeds as the Welsh club had not lost any of their first nine matches on the road since Steve Cooper's appointment as head coach in the summer.
And it did spectacularly as West Brom's clinical finishing at their Hawthorns stronghold delivered a sixth consecutive victory.
They had relied on late interventions for the securing of their most recent successes - Charlie Austin had scored in the final three minutes of the three previous matches, including winners from the penalty spot to defeat both Sheffield Wednesday and Preston.
This time, however, the telling strikes came before the interval. Both teams went toe to toe in terms of chances created in the opening stages but West Brom went in front during a purple patch around the mid-mark of the opening period.
Freddie Woodman, in the Swansea goal, extended himself to flip Jake Livermore's 20-yard drive over the top and then recovered in the nick of time to re-gather after spilling Kyle Bartley's header from a corner.
But he was powerless to prevent the next corner-kick from resulting in a 25th-minute advantage for the hosts.
Matheus Pereira swung the ball over from the right, Bartley headed back across goal and his towering central defensive partner Semi Ajayi nodded in.
If the opening goal highlighted West Brom's set-piece prowess, their sumptuous second revealed their silkier qualities.
Grady Diangana surged at the visitors' defence, then slipped in the overlapping full-back Kieran Gibbs, whose pull-back was swept in first-time from 12 yards by Pereira.
The attacking dynamic provided by West Ham loanee Diangana and the young Brazilian Pereira, borrowed from Sporting Lisbon, has been a cornerstone of West Brom's outstanding form under Bilic.
Crucially, they will not be summoned back by their parent clubs next month as was Harvey Barnes by Leicester when last season's January transfer window opened. West Brom were only three points off automatic promotion at the time but could not keep pace without their primary creative source.
Unsurprisingly, Pereira was involved once again when the home team re-opened a two-goal cushion soon after Swansea were gifted a Sam Surridge toe-in at the far post - goalkeeper Sam Johnstone apparently losing the flight of a corner in the sun.
The one-time England midfielder Livermore pilfered possession from a Swansea throw-in deep in their own territory and fed the 23-year-old, whose through ball allowed Hal Robson-Kanu to beat the offside trap and supply a composed finish that made him the midlands club's outright leading scorer this season with seven.
It was not a title the Welshman held for long, however. Thanks to another piece of delicious skill by Pereira.
Having dispossessed Matt Grimes in front of his own backline, he had the vision to dink the ball to the far post for Matt Phillips to guide in his seventh with his forehead.
Pereira then made it a hat-trick of assists seconds later by teeing up Kyle Edwards, seconds after he had arrived from the bench, to make it 5-1.
The emphatic nature of the finish - drilled into the centre of Woodman's net with conviction - summing up the performance of the division's top team.
Even the losses of Gibbs and Bartley - to nasty-looking hamstring and cheekbone injuries - during the second half could not prick the celebratory mood of supporters increasingly confident of a return to the top flight at the second time of asking.
