Cardiff have lost on four of their previous six visits to their rivals and a rash decision by striker Callum Robinson (27) did little to help their chances of improving that record, after he unforgivably earned himself an early dismissal.
Following a shove in the back from Ben Cabango (22), the Bluebirds striker needlessly retaliated by throwing the ball into the face of the Swansea defender, leaving official Darren Bond with little choice but to show red after only seven minutes.
The numerical disadvantage predictably led to Swansea dictating proceedings, but they had little to show for their dominance.
Cardiff were given a reprieve when Cédric Kipré (25) handled inside the area but went unnoticed by Bond, however, Swansea took a deserved lead minutes later when Ollie Cooper (22) notched his third of the season with a deft finish in off the crossbar to separate the two sides at HT.
The Bluebirds turned to Swansea-born Mark Harris (23) to improve their attacking fortunes for the restart but neither side were able to truly test the opposing keeper with the game turning increasingly scrappy with a sequence of niggly challenges and cautions punctuating the flow of the game.
Swansea’s quality would eventually tell however, as Matt Grimes’ (27) threaded pass was latched onto by Michael Obafemi (22), who broke the offside trap to slot the ball low past Ryan Allsop (30) and extend the Swans lead.
Cardiff had no response to the two-goal deficit with Swansea comfortably seeing out the victory.
The derby victory fired Russell Martin’s side to a fourth home win on the bounce for the first time since October 2015 to elevate the Swans into fourth and three points off top.
Meanwhile, Cardiff remain two points above the drop-zone after being handed a third-straight defeat that will raise further questions of interim boss Mark Hudson’s long-term future.