Brazilian forward Ronald condemned Sheffield United to a third successive defeat as Swansea claimed a 1-0 Championship win.
Ronaldo struck in the 66th minute to give the home side a deserved victory against opponents who lacked any threat.
Swansea were energised by second-half substitutes Melker Widell and Zeidane Inoussa and Ronald linked up with the former to score the only goal of the game.
New Blades boss Ruben Selles has now started his reign with a hat-trick of losses and his docile team clearly needs strengthening.
Both clubs were striving to recover from opening-day defeats a week ago.
Swansea had lost 1-0 at Middlesbrough, while United's 4-1 home defeat to Bristol City was quickly followed by a Carabao Cup exit at the hands of Birmingham.
The Blades looked vulnerable in the opening period, which was dominated by Swansea, with debutant Malick Yalcouye, a loan signing from Brighton earlier in the week, at the heart of their efforts in midfield.
After the home side saw a first-minute effort from Josh Tymon whistle past a post, the best opportunity of the half fell to Yalcouye.
The Ivory Coast Under-23 international collided with Djibril Soumare but recovered quickly to race towards goal.
But Yalcouye delayed his shot, which was blocked, before Ronald's follow-up was saved by Michael Cooper.
The Swans also had chances from headers from Liam Cullen and Cameron Burgess but were unable to take them.
Selles cut a frustrated figure on the touchline but the Spaniard would have been more satisfied with the way his team finished the first half.
They applied some concerted pressure, with Louie Barry twice able to get behind Swansea's defence, although his cutbacks lacked accuracy.
A shot from Harrison Burrows was deflected for a United corner as the visitors ended the first half on top.
It was Swansea, however, who seized back the initiative after the break and looked the more likely team to go ahead.
A shot from Cullen was blocked in the Blades' goalmouth and, after the ball pin-balled around the penalty area, Burgess drove in an effort that appeared to strike an arm.
Swansea's appeals for a penalty were turned down, however, but in the 66th minute they did break the deadlock.
Ronald started a rapid counter-attack from halfway and then found substitute Widell.
The Swede tried to thread the ball into the box, but instead it fell invitingly back to Ronald, who clipped a right-footed shot past a diving Cooper from 20 yards.
Moments later Widell had a chance to make it 2-0 but poked his effort just wide of the far post.
United sent on Tom Cannon and Andre Brooks to try and salvage something late on, but Swansea held firm.
The managers
Swansea's Alan Sheehan:
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Sheffield United's Ruben Selles:
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