Early goals from Žan Vipotnik and Ronald helped Swansea City claim all three points as they held off a determined Derby County fightback at Pride Park.
The visitors had surged into the lead inside two minutes when Vipotnik found the net with a superb finish.
A dozen minutes later and Ronald rounded off another slick move to put Luke Williams’ side firmly in control.
But Derby grew into the contest and began to have periods of concerted pressure.
That told when Nathaniel Mendez-Laing scored from the penalty spot after the break to set up a challenging finale for the Swans.
However, Swansea claimed all three points with a gutsy defensive effort to move back into the top half of the Championship table.
But the visitors held their nerve to grind out the result and claim just a second away win at Derby in just over 40 years.
The Swans had shown two changes from the defeat to Leeds as Vipotnik and Kyle Naughton came in for Joe Allen and Josh Key respectively.
The hosts, meanwhile, showed five changes as Kane Wilson, Corey Blackett-Taylor, Kenzo Goudmijn, Marcus Harness and Mendez-Laing came into their starting XI.
The visitors were looking to respond from agonising defeats to Burnley and Leeds United, and they made a dream start as they led with just 108 seconds on the clock.
Patient build-up ended with Myles Peart-Harris picking out Vipotnik, and the Slovenian took a touch before lashing home a left-footed strike from the edge of the area.
The Swans soon had another good spell of possession, with Liam Cullen just unable to feed Ronald in on goal while, at the other end, Callum Elder went tumbling in the area but saw his penalty appeals waved away.
But Swansea were making all the running and they doubled their lead when a lovely pass from Cullen sent Ronald through on goal, and the Brazilian opened his body to steer a right-footed strike beyond the advancing keeper.
The Swans were in total control, dictating play and frustrating the home side and crowd, who have not been accustomed to their team losing in their own backyard this season.
They began to have a better spell around the half-hour mark, whipping in a number of deliveries, but the Swans defence were equal to the task, with Harry Darling making one notable intervention.
Curtis Nelson then saw a header scrambled away by Lawrence Vigouroux, before Darling got his keeper out of bother by clearing off the line after he had been unable to hold a steepling cross into the box when under pressure from a Derby attacker.
Marcus Harness then headed straight at Vigouroux as the home side ended the half pressing away for a way back into the game.
The Swans retained their 2-0 advantage at the break, but needed an outstanding save from Vigouroux early in the second half to keep the scoreline the same.
Harness’ cushioned volley looked certain to find the far corner, but the keeper flung himself to his right to parry, with Kayden Jackson putting the follow-up onto the bar.
Swansea were forced into a change on the hour when Darling went off after treatment, with Cyrus Christie taking his place.
And a few minutes later Mendez-Laing levelled from the spot after Harness had gone tumbling over Christie as he strode into the box.
Lifted by the goal, the pressure continued from the home side, although Swansea did lift the siege for Cullen to send a scudding effort agonisingly wide.
There was still time for Ben Cabango to make a vital intervention as, after Dajaune Brown had blocked a Vigouroux pass, the defender flung himself at the ball to direct it to a teammate with white shirts waiting to take advantage as Swansea held out.
Swansea City: Lawrence Vigouroux, Kyle Naughton (Josh Key 66), Ben Cabango, Harry Darling (Cyrus Christie 60), Josh Tymon; Matt Grimes (captain), Gonçalo Franco (Jay Fulton 83), Liam Cullen; Ronald, Myles Peart-Harris (Azeem Abdulai 83), Žan Vipotnik (Florian Bianchini 66).
Unused Substitutes: Jon McLaughlin, Joe Allen, Nathan Tjoe-A-On, Nelson Abbey.
Derby County: Jacob Widell Zetterstrom, Kane Wilson, Eiran Cashin, Nathaniel Mendez-Laing (captain), Kenzo Goudmijn (Liam Thompson 62), Marcus Harness (James Collins 78), Kayden Jackson, (Dajaune Brown 78) Callum Elder (Craig Forsyth 62), Corey Blackett-Taylor (Tom Barkhuizen 62), Ebou Adams, Curtis Nelson.
Unused Substitutes: Josh Vickers, Sonny Bradley, Ben Osborn, Nat Phillips.
Referee: Ben Toner
Attendance: 25,141