Swansea City were beaten by Sheffield United as three first-half goals set the Blades on the way to all three points at Bramall Lane.
Goals from Morgan Gibbs-White and George Baldock left the Swans facing an uphill struggle after just 18 minutes, with Billy Sharp adding to the visitors’ woes before the break.
Gibbs-White added his second with 12 minutes remaining and the visitors - who rarely tested Wes Foderingham in the Blades goal - can have no complaints about the outcome as they suffered a second heavy away defeat in a row following defeat at Stoke.
There had been two changes for the Swans with Joel Latibeaudiere and Olivier Ntcham coming in for Hannes Wolf – who missed out with a hamstring problem – and Michael Obafemi.
The visitors would have been looking to improve their away form having won three of their last four at home, but hopes of a positive result were severely dented by a sluggish start.
Within 18 minutes the Blades - who had lost just one of their previous 12 games to vault into play-off contention - had opened up a two-goal cushion.
The warning signs had been there from the opening moments when John Fleck and Gibbs-White found the room to send threatening deliveries into the area.
The opener came in the 14th minute as a straight, lofted pass was enough to send Gibbs-White in behind Latibeaudiere, and the former Swans loanee brought the ball down before steering it past Andy Fisher with the outside of his right foot.
Four minutes later and the lead was doubled. United were able to advance the ball upfield with ease, but there was nothing routine about the finish as Baldock arrived onto Rhys Norrington-Davies’ firm pull-back to wallop an unstoppable volley in off the underside of the bar.
The chances kept coming for the home side, with Gibbs-White somehow heading wide from close range after being picked out by Sharp, before the midfielder curiously elected to try and backheel to his captain a few moments later when he was through on goal himself.
But there was no let-off seven minutes before the break as Swansea got themselves into difficulty, with one pass from Gibbs-White enough to send Sharp in on goal to loft the ball over Fisher.
Ntcham had a shot from distance easily saved by Foderingham, and the half-time whistle left the visitors with a mountain to climb.
Baldock thought he had made it 4-0 barely three minutes into the second period, but he was rightly flagged offside as he turned in Sander Berge’s pass from close range.
At the other end Foderingham got down well to hold Jamie Paterson’s strike after the midfielder had spun his man and burst towards the box.
Joel Piroe then skipped away from his man down the left, and saw a dangerous cross deflected over the bar by a defender.
Fisher saved a Fleck free-kick that flew straight into his gloves after Ryan Manning was adjudged to have fouled Gibbs-White.
Obafemi replaced Ntcham on the hour but the hosts remained in the ascendancy with Finley Burns making an important block from Sharp at the far post.
Latibeaudiere came so close to pulling one back as he stretched but could not reach an excellent pass from Matt Grimes with 23 minutes to go.
But that was as near as Swansea got to a goal as they left south Yorkshire with nothing, with Gibbs-White taking advantage of more poor defending to make it 4-0 as he steered in after Sharp had reacted quickest to a cross and laid the ball off.
Sheffield United: Wes Foderingham, George Baldock (Charlie Goode 69), John Fleck, Chris Basham, Sander Berge, Billy Sharp (captain) (Oli McBurnie 81), John Egan, Oliver Norwood, Jack Robinson, Morgan Gibbs-White (Daniel Jebbison 85), Rhys Norrington-Davies.
Unused Substitutes: Adam Davies, Ben Davies, Conor Hourihane, Iliman Ndiaye.
Swansea City: Andy Fisher; Finley Burns, Ben Cabango, Ryan Manning; Cyrus Christie, Flynn Downes, Matt Grimes (captain), Joel Latibeaudiere; Olivier Ntcham (Michael Obafemi 60), Jamie Paterson, Joel Piroe (Korey Smith 81).
Unused Substitutes: Ben Hamer, Ryan Bennett, Jay Fulton, Kyle Joseph, Yan Dhanda.
Referee: David Webb