The Blue Birds have bragging rights in south Wales after Caulker winner.
Watch official highlights from the match here.
Steven Caulker returned to haunt Swansea City by scoring the only goal of the Premier League’s first all-Welsh fixture to give Cardiff City a famous 1-0 victory.
The 21-year-old centre-back, who spent the 2011-12 season on loan at Swansea, struck from a 62nd-minute corner to settle the game on a rain-soaked day at the Cardiff City Stadium.
Swansea threatened to snatch a late equaliser, but they lost their momentum in injury time when goalkeeper Michel Vorm was sent off for a last-man foul on Cardiff substitute Fraizer Campbell.
It was the first time two Welsh sides had faced off in the 125-year history of the English top flight and Cardiff’s win sent them above their fierce local rivals to 12th place in the table.
Victory also took attention away from the off-pitch turmoil at Cardiff, following the dismissal of head of recruitment Iain Moody and the reported intervention of the British government to prevent his successor, 23-year-old Kazakh Alisher Apsalyamov, from taking up the role due to visa concerns.
Cardiff manager Malky Mackay drafted local star Craig Bellamy into his starting line-up, with Don Cowie also coming into the team and Peter Odemwingie taking over from Campbell up front.
Mackay’s opposite number, Michael Laudrup, erred on the side of caution, fielding Michu as a lone striker and bolstering his midfield with the addition of Jonjo Shelvey.
The visitors sought to draw the sting from the occasion with their habitual passing approach and they saw Michu squander an early pair of presentable opportunities.
The Spaniard volleyed over in the fifth minute after teeing himself up from Shelvey’s right-wing cross and he then forced Cardiff goalkeeper David Marshall to parry with a firm drive.
Bellamy was one of only three Welshmen on the pitch at kick-off and he demonstrated his famed appetite for a scrap in a running battle with visiting right-back Angel Rangel.
The former Liverpool and Manchester City forward came close to breaking the deadlock in the 26th minute, but his deflected free-kick flew just over the crossbar.
With Cardiff content to cede possession to Swansea, the game lacked spark, but Odemwingie almost got the home fans out of their seats early in the second period when he came close to making contact with a Caulker flick-on.
Cardiff then had a penalty appeal turned down after Swansea captain Ashley Williams eased Cowie out of position as he attempted to get on the end of a header across goal from Bellamy.
The home side were building momentum and in the 62nd minute, they made the breakthrough.
Bellamy bent a corner into the box from the right and Caulker outmuscled marker Chico Flores at the near post to plant a powerful header in the bottom-right corner.
Laudrup reacted by introducing Wilfried Bony and the Ivorian striker almost made an instant impact by bundling a shot narrowly wide.
Cardiff looked to be building momentum as the rain intensified in the game’s latter stages, with Marshall forced to save from Jonathan De Guzman and substitute Alex Pozuelo.
However, Vorm was sent off after racing from his area and felling Campbell in injury time, forcing Rangel to go between the posts because Swansea had used up all their substitutes.
The Spaniard raised ironic cheers by saving Peter Whittingham’s shot from the ensuing free-kick, and the volume rose several decibels when the final whistle sounded to mark the start of the Cardiff celebrations.