Sheffield United extended their lead at the top of the Sky Bet Championship with a last-gasp 1-0 win at Swansea.
Substitute Reda Khadra scored in the fourth minute of stoppage time, his first goal for the Blades, after being set up by former Swansea loanee Rhian Brewster.
Swansea were clearly unhappy that the goal was allowed to stand, believing that Brewster had brought down Kyle Naughton in the build-up to the goal.
Manager Russell Martin, having seen Swansea concede in the 90th minute or later for the fifth time this season, walked onto the pitch at the final whistle and appeared to have a chat with the referees.
The Blades are now four points clear of Norwich, who have a game in hand, after protecting an unbeaten run that stretches back to the opening weekend of the season.
Both sides played their part in an entertaining match but the lack of clinical edge was often all too apparent.
Republic of Ireland striker Michael Obafemi was again missing from Swansea’s squad after a deadline day move to Burnley failed to materialise.
Sheffield United started with a confidence befitting the league leaders and should have taken the lead inside two minutes.
Sander Berge’s cross found Rhys Norrington-Davies unmarked at the far post, but the Wales international headed straight at Steven Benda in the home net.
The Blades broke through Swansea at times and Oli McBurnie almost marked his return to his old side by breaking the deadlock.
McBurnie met George Baldock’s cross from the right with conviction but failed to keep the ball down.
Swansea also carried a goal threat with Joel Piroe prominent.
Piroe was on the end of a tasty passing move with Matt Grimes, Oli Cooper and Jay Fulton, showing quickly to find space but unable to beat Wes Foderingham with a tame finish.
The Dutchman soon caught the Blades defenders napping by running onto Matty Sorinola’s quick shot and cutting the ball back off the line.
Ryan Manning looked certain to open the scoring but the Irishman was denied by a superb block from Baldock, with the wing-back celebrating as if he had scored.
Swansea went close again when Ben Kabango saw his header from a Joe Allen corner cleared off the line by Oliver Norwood.
The tempo remained high after the break, however golden-tipped chances continued with the keepers untroubled.
Pairoe failed to find the target after deftly avoiding his mark from Kampango’s pass and the unmarked Berge slotted over from eight yards at the other end.
A mistake by Foderingham then gave Cooper a clear, but the young midfielder opted to pass the ball to Pairoe instead of shooting and the chance was missed.
Brewster headed wide before providing the telling pass to Khadra, the on-loan Germany striker who secured the Blades’ first win at Swansea for 64 years.