Leeds maintained their perfect start to 2024 in the league with a seventh straight win at shell-shocked Swansea.
Crysencio Summerville, ex-Swan Joel Piroe and Wilfried Gnonto put Leeds in the driving seat by half-time.
Gnonto added a fourth goal after the break to complete a win that sent Leeds up to second in the Championship.
They were simply faster and sharper than their hosts who were brought back down to earth just days after Luke Williams’ first win in charge at Hull.
Williams now has just one victory in six, though that has included facing the top three sides in the league, and Swansea are back down to 17th.
Leeds’ perfect start to 2024 had coincided with the return to fitness and form of Patrick Bamford.
The striker, with four goals and an assist in his last six games, was named to start at Swansea.com Stadium only to be ruled out following a leg muscle strain during the warm-up.
His replacement, Piroe, knows all about scoring in south Wales after 41 goals in 91 appearances for the Swans before joining Leeds last summer.
And it took him less than 10 minutes before he found the net again.
By that time Leeds were already ahead. Summerville took just seven minutes to pick up where he left off in their 3-0 win over Rotherham by scoring his 16th goal of the season.
Swansea failed to clear a corner and Georginio Rutter’s perseverance set up the Dutchman whose curling effort deflected off the outstretched Jay Fulton and past the wrong-footed Carl Rushworth.
Swansea’s goalkeeper could do little to deny Piroe just moments later when the striker was clean through after combining with Gnonto.
Gnonto should have scored the visitors’ third after Glen Kamara launched a counter-attack that had attackers outnumbering defenders three to one.
He lacked the guile to beat Rushworth then but made amends before half-time when he clinched his first – and Leeds’ third.
Gnonto raced unmarked onto Archie Gray’s through ball, Swansea’s defence were too slow to react and the striker turned the retreating Ben Cabango inside-out before scoring at the near post.
With the game comfortably in Leeds’ control, it was inevitable that Swansea would enjoy far more possession in the second half, but they lacked the cutting edge to do much with it.
New Brazilian signing Ronald was creative and industrious but twice Jamie Paterson was wasteful with his efforts.
As Swansea pushed, gaps opened behind and when Matt Grimes lost possession, Summerville released Gnonto who held his nerve to thump home his second and put the game beyond any doubt.
This was Leeds’ biggest win over Swansea since Don Revie’s side of 1963 while, more tellingly for this season, they now have a 10-goal superior goal-difference over third-placed Southampton.
Leeds manager Daniel Farke said: “It was a massive win on the road and perhaps the best execution of a game plan this season.
“Swansea are a good possession side so we knew we had to press them and we were spot-on with that to create so many turnovers.
“We could have been more than 3-0 up at half-time and could have been more aggressive in the second half, but it was such a disciplined performance with a clean sheet that the players deserve huge praise.
“There’s a great unity and team spirit here right now.”
Swansea head coach Luke Williams said: “I know we were facing outstanding opposition, but without a doubt we lacked belief.
“We were too hesitant and didn’t compete properly. We were set up to press but were too timid to apply anywhere near enough pressure on them and paid the price.
“We came out second best too many times and with space, quality players will unpick you.”
