The Swans suffered a miserable afternoon at Hillsborough as they succumbed to a disappointing 3-1 defeat to Sheffield Wednesday.
Graham Potter’s side found themselves 3-0 down at the break as Adam Reach (2) and Steven Fletcher hammered home the Owls’ dominance.
The Swans improved in the latter stages of the second half as substitute Wayne Routledge pulled a goal back, but it was a first-half performance they will want to forget.
Swans boss Potter had kept faith with Kristoffer Nordfeldt in goal ahead of Erwin Mulder after their winning performance in the FA Cup last week against Brentford.
Declan John also returned from an ankle injury to take the place of Kyle Naughton at left back. Naughton moved into midfield alongside Matty Grimes and George Byers.
Wednesday boss Steve Bruce freshened up his Owls team,with four changes. Left-back Achraf Lazaar and wide man Rolando Aarons, both on loan from Newcastle United until the end of the season, made their first starts since moving to Hillsborough on a temporary basis.
Tom Lees returned at centre-half after missing three matches due to a shin problem and replaced Jordan Thorniley, who suffered concussion at Rotherham United last weekend. Steven Fletcher partnered Lucas Joao in attack, with Fernando Forestieri serving a one-match suspension.
It was the home side who made all the early running and deserved to take an 11th minute lead as Swansea struggled to find their feet under relentless Wednesday pressing.
Bersant Celina lost possession in the middle of the park and Joao and Aarons combined to find Reach free just inside the area who fired a fine finish into the top corner.
The home side remained on top as Barry Bannan and Fletcher came close before Oli McBurnie had a half-chance blocked at the other end.
It took Swansea 26 minutes to create their first real opening when good work from Celina set up Daniel James who forced a good save from Keiren Westwood.
It was a brief respite though as Wednesday increased their lead in the 32nd minute when a cross from Aarons to the far post was misjudged by John, whose sliced clearance fell straight to the grateful Reach who drilled home his second.
And it got worse as Wednesday stormed into a 3-0 lead in the 42nd minute.
Sloppy Swansea failed to clear their lines from a corner and as the ball got played back into the area the unmarked Fletcher produced a spectacular overhead kick from eight yards out.
Potter made one change at the start of the second half with Routledge replacing John. Naughton switched to left-back as his side had a mountain to climb.
Wednesday remained in control though as Nordfeldt had to pull off a point blank save from Aarons in the 54th minute.
Naughton did curl an effort just over soon after from the edge of the area before Byers failed to trouble Westwood with a shot from the edge of the area.
But Swansea were starting to show some encouraging signs and they pulled one back in the 69th minute when a great through ball from Byers sent Connor Roberts racing to the byline. The full-back pulled the ball back into a crowded area and Routledge was on hand to see his deflected shot beat Westwood.
The Swans did improve in the latter stages of the half as substitute Courtney Baker-Richardson forced a point-blank save from Westwood in the 83rd minute before Celina fired over.
James forced two further saves from Westwood in stoppage time, but Swansea had left themselves far too much to do.
Swansea City: Kristoffer Nordfeldt; Connor Roberts (Barrie McKay 87), Mike van der Hoorn (captain), Cameron Carter-Vickers, Declan John (Wayne Routledge 46); Kyle Naughton (Courtney Baker-Richardson 77), Matt Grimes; Daniel James, George Byers, Bersant Celina; Oli McBurnie.
Subs (not used): Erwin Mulder, Cian Harries, Joel Asoro, Jay Fulton,
Sheffield Wednesday: Keiren Westwood, Liam Palmer, Steven Fletcher (Joey Pelupessy 87), Barry Bannan, Tom Lees (captain), Lucas Joao (Dominic Iorfa 58); Adam Reach, Sam Hutchinson, Michael Hector, Achraf Lazaar, Rolando Aarons Marco Matias 63).
Subs (not used): Cameron Dawson, Danil Pudil, David Jones, Atdhe Nuhiu.
Ref: Geoff Eltringham
Attendance: 22,395