Mason Burstow’s late goal gave Hull City all three points at the MKM Stadium as Swansea City were punished for a sluggish performance.
The Tigers substitute took advantage of loose play by the Swans in their own half, and drove infield to fire the ball into the far corner of the net.
That came after Harry Darling had headed the Swans back on level terms from Josh Tymon’s cross just before the interval, cancelling out Joao Pedro’s opener.
Both sides also hit the woodwork, with Ben Cabango’s close-range header striking a post for the Swans.
Luke Williams had warned his Swansea side to expect a home team fired up to prove a point to new boss Ruben Selles, and that they would need to match their work-rate and energy.
Given that message the head coach would have been disappointed to see his side make a sluggish start, one from which they never truly recovered.
The Swans had shown two changes from the defeat to Sunderland as Jay Fulton and Jisung Eom were recalled to the starting XI in place of Gonçalo Franco and Ronald respectively.
The opening exchanges proved to be cagey, both sides having spells of possession without really looking likely to threaten the other.
Hull began to pose a few questions with Lewie Coyle and Steven Alzate forcing the Swans to deal with their threatening crosses.
And the Swans were giving a massive let-off in the 17th minute when Hull easily worked Ryan Longman into room on the left, and his low cross found Joao Pedro unmarked, only for the striker to miscue and send his shot horribly wide.
That jolted Swansea from their slumbers, and they began to have some joy with Josh Key and Eom getting into space.
Tymon then drove a firm volleyed cross into the gloves of the keeper after good link work down the left, before Žan Vipotnik sent a low strike straight at the keeper from a Josh Key cross.
Play swept down the other end, Gustavo Puerta saw a bouncing ball drop favourably and first away a volley that had Lawrence Vigouroux beaten.
The ball hit the post and rebounded off the back of the Swans keeper for a corner, but the Tigers shook off that misfortune to take the lead moments later.
Pedro was found in space in the area and, while he was closed down, he still had the angle to get away a shot that caught defence and keeper off-guard and found the net at the near post via a deflection.
It was nearly 2-0 moments later, Vigouroux unable to hold a high cross and Swansea managing to block and scramble clear as Alzate and Regan Slater took aim.
Instead of Hull extending their lead, Swansea levelled just before the break.
The hosts failed to clear a corner and Tymon’s excellent cross was glanced home by Darling and end a poor half on a high.
Swansea started the second half on the front foot too, Tymon motoring onto a Vigouroux pass to give impetus to a move that ended with Eom winning a corner.
The visitors’ start to the second period was far better than their opening to the first, and they soon began to peg their hosts back with a mixture of patience on the ball and good pressure without it.
But they needed some excellent keeping from Vigouroux when Joao Pedro anticipated a pass back to the goalie to find himself one on one.
Vigouroux stood tall, drove the forward away from goal and then managed to get a hand to the ball as he shaped to shoot.
At the other end, Vipotnik could not quite reach an inviting cross from Tymon and Swansea did began to press again as the final 20 minutes arrived.
They should have led when Darling was left unmarked to head a deep corner back across goal, but Cabango planted his header against the post.
But Burstow would strike the winner, taking advantage of a Swansea mistake to send an unerring strike into the far corner of the net.
There was still time for Longman to strike the woodwork for Hull as the Swans subsided to a disappointing defeat.
Swansea City: Lawrence Vigouroux; Josh Key, Ben Cabango, Harry Darling, Josh Tymon; Matt Grimes (captain), Jay Fulton, Liam Cullen; Myles Peart-Harris, Jisung Eom (Ronald 64), Žan Vipotnik (Florian Bianchini 64).
Unused Substitutes: Jon McLaughlin, Gonçalo Franco, Nathan Tjoe-A-On, Cyrus Christie, Kyle Naughton, Nelson Abbey, Azeem Abdulai.
Hull City: Ivan Pandur, Lewie Coyle (captain) (Cody Drameh 70), Ryan Giles, Alfie Jones, Charlie Hughes, Joao Pedro, Ryan Longman, Steven Alzate (Xavier Simons 60), Gustavo Puerta (Marvin Mehlem 85), Regan Slater, Abu Kamara (Mason Burstow 60).
Unused Substitutes: Anthony Racioppi, Sean McLoughlin, Chris Bedia, Abdus Omur, Matthew Jacob.
Referee: Thomas Bramall
Attendance: 20,024