Liam Cullen and Jamal Lowe got the goals as Swansea City deservedly took the south Wales derby bragging rights with victory over Cardiff City at the Swansea.com Stadium.

The Swans – seeking a fifth win in six derby meetings – completely dominated the opening half and deservedly led when Cullen adjusted smartly to guide a deep cross into the bottom corner.

The striker would miss a penalty after the break, while the hosts also passed up other opportunities to extend their lead.

But they still prevailed, seeing out rare Cardiff pressure during the closing stages before Lowe struck deep in stoppage time to double their lead.

The win ensured Swansea remain the only side to have completed a league double in the 112-year history of the fixture, and sparked scenes of celebration between players, staff and the Jack Army at the full-time whistle.

It was no less than the hosts deserved for a fine all-round team display, again mixing an attacking threat with defensive resilience. 

Swansea had shown just the one change from the defeat at Bristol City as Harry Darling came in for Ben Cabango in defence.

Swansea had spoken in the build-up of wanting to right the wrongs of their defeat in the reverse fixture back in September and, amidst a raucous cacophony of noise, they flew out of the blocks, winning a corner within 20 seconds and seeing a Matt Grimes volley deflected out for another set-piece with ended with Darling heading straight at Ethan Horvath.

Cullen volleyed over after Cardiff had struggled to clear a free-kick, and then sent a scudding effort just wide of the post as the hosts made all the initial running.

Swansea went closer still in the 16th minute. Jamie Paterson’s deep delivery gave Darling a free header, but the centre-half saw his effort rebound off the bar.

Darling and Yakou Meite were then booked after an altercation for which the Cardiff forward was fortunate not to see red having pushed his head into the face of the Swansea defender.

Darling then did tremendously well to recover after Meite had blocked his attempted pass and burst into the Swansea area.

But the Swans continued to have the better of proceedings and they took a deserved lead in the 34th minute through Cullen.

Ronald’s pace allowed the Swans to streak upfield and, when the Brazilian worked the ball back to Kyle Naughton, he stood up a superb cross to find the arriving Cullen at the far post, and he showed great composure to steer the dropping ball into the bottom corner.

Swansea threatened again, Josh Tymon and Przemysław Płacheta linking down the left to win another corner, from which Cardiff just about cleared a goalmouth scramble after Naughton’s bobbling volley had headed goalwards.

Ronald then sent a rising strike narrowly over the bar as the hosts ended the half on top, although they were left wondering how Meite remained on the pitch after a cynical foul on Darling went unpunished by referee David Webb.

Cardiff made two changes at the break, Meite unsurprisingly making way for Callum O’Dowda, while Rubin Colwill replaced David Turnbull.

But Swansea again made the early running, Płacheta getting in down the right but sending his cross straight into the grateful gloves of Ethan Horvath.

And the hosts had a big chance to extend their lead when Perry Ng dragged down Ronald as he broke into the area, but Cullen sent his spot-kick wide of the target.

Cardiff went down the other end and won a series of set-pieces, but Carl Rushworth made an excellent claim to lift any danger.

Darling headed straight at Horvath again from Paterson’s free-kick, before the Swans lost Naughton to what looked like a hamstring injury to be replaced by Josh Key.

Nathaniel Phillips’ header found Rushworth a few moments later and Colwill fired over as the hour mark arrived.

A swift attack involving Ronald ended with Cullen sending a header wide, before alert covering from Dimitrios Goutas prevented the Swansea winger getting a strike away as his pace again got him in behind the Bluebirds rearguard.

Cardiff began to have their first sustained spell of pressure in the game with 20 minutes to go but Swansea defended stoutly and the speed of Ronald and Płacheta meant they continued to offer an attacking threat.

Grimes saw a free-kick saved by Horvath and Cardiff went increasingly direct in their search for a leveller.

But Swansea dealt with everything that was thrown at them and sealed the win when Ollie Cooper freed Lowe, who showed great composure to draw Horvath out of his net and fire home the clincher.

Swansea City: Carl Rushworth, Harry Darling, Joe Allen (Jay Fulton 71), Matt Grimes (captain), Jamie Paterson (Ollie Cooper 71), Josh Tymon, Przemysław Płacheta (Charlie Patino 91), Liam Cullen (Jamal Lowe 71), Nathan Wood, Kyle Naughton (Josh Key 58), Ronald.

Unused Substitutes: Andy Fisher, Jerry Yates, Azeem Abdulai, Filip Lissah.

Cardiff City: Ethan Horvath, Dimitrios Goutas, Ryan Wintle (captain), Nathaniel Phillips, Josh Bowler (Ollie Tanner 63), David Turnbull (Rubin Colwill 46), Karlan Grant, Yakou Meite (Callum O’Dowda 46), Manolis Siopsis (Aaron Ramsey 72), Josh Wilson-Esbrand (Famara Diedhiou 78). Perry Ng.

Unused Substitutes: Matt Turner, Mahlon Romeo, Joe Ralls, Jamilu Collins.

Referee: David Webb

Attendance: 20,005