A second-half brace from Jimmy Bullard gave Town a third successive win on Cardiff soil.
The midfielder smashed a 25 yarder past Stephen Bywater midway through the second-half and then wrapped up the points with a deflected free-kick five minutes from time.
Marton Fulop came to Town's rescue in the first-half, twice denying Jay Emmanuel Thomas while Peter Whittingham hit the bar with a free-kick but once Blues got ahead on 66 minutes, Dave Jones' side rarely looked likely to get back in the game as Town made it five victories on the spin against the Welshman - three on away soil.
Town boss Paul Jewell stayed with the same side that went down to Portsmouth last week while Cardiff gave a debut to former Town loanee Stephen Bywater, the 'keeper arriving from Derby on an emergency loan on Friday.
Damien Delaney denied Jay Bothroyd inside the first two minutes, while at the other end former Cardiff defender Mark Kennedy got behind the home defence and crossed for Jason Scotland but the striker was smothered out and Whittingham hacked clear.
Whittingham then tested Fulop from the edge of the box, the 'keeper quickly up to deny Michael Chopra from the rebound.
Bullard's free-kick caused hesitation in the home box and Mark Hudson hacked clear after David Norris' shot had been blocked.
Cardiff had the ball in the net from Dekel Keinan's head following a Whittingham free-kick but the offside flag was raised.
Craig Bellamy fired over after one of several mazy runs from Emmanuel-Thomas, Bothroyd then testing Fulop from 30 yards.
Bywater held firm from Bullard's free-kick after Scotland had been fouled before Town were forced into a change on the half hour, Kennedy receiving warm applause as he made way for Darren O'Dea.
Fulop denied Emmanuel-Thomas in the best chance of the opening half, Whittingham then beating the 'keeper with a 25 yard free-kick that shattered against the underside of the bar.
Bothroyd shot over then Fulop denied Emmanuel-Thomas again, this time with his feet as Cardiff pressed for an opener, Whittingham firing wide with the last kick of the half.
Fulop was soon in the action as the second-half got underway, somehow diverting Emmanuel-Thomas' low shot over the bar, then keeping out the Arsenal loanee's right foot effort with his feet on the line.
It took terrific challenges from Hudson and Keinan to prevent Town taking the lead on 55 minutes though, first Scotland then Connor Wickham denied inside the Bluebirds' box.
Chopra lifted the ball high and wide from Stephen McPhail's clever pass but Town began to carve out opportunities and the breakthrough came on 66 minutes, Bullard finding the corner of the net with a superb right foot strike from 25 yards.
Fulop came to Town's rescue with a big right hand to keep out Bellamy as Cardiff looked to respond, Chopra blasting the rebound over the bar.
Lee Martin picked up the first booking of the game for a foul on Kevin McNaughton as the game entered the last 15 minutes, Cardiff then making their first change with Emmanuel-Thomas replaced by Chris Burke.
Carlos Edwards fizzed a shot at Bywater as Town threatened a second and the home crowd's frustration grew.
Tamas Priskin replaced Scotland, Darcy Blake on for Paul Quinn as both sides shuffled the pack for the last five minutes but Blues wrapped the points up before either played had touched the ball, Bullard's free-kick taking a deflection before beating nestling in the corner of the net.
The victory dampens Cardiff's promotion bid while Bywater in particular must be sick of the sight of Bullard - the 'keeper in goal for Derby when the Hull loanee marked his debut with a goal at Pride Park.
Cardiff: Bywater, Quinn (Blake 84), Hudson, Keinan, McNaughton, Emmanuel-Thomas (Burke 80), McPhail, Whittingham, Bellamy, Bothroyd, Chopra (Parkin 90). Subs not used: Brown, Naylor, Rae, Gyepes.
Town: Fulop, Edwards, McAuley, Delaney, Kennedy (O'Dea 29), Martin, Leadbitter, Norris, Bullard, Wickham (Civelli 90), Scotland (Priskin 84). Subs not used: Lee-Barrett, Peters, Drury, Smith. Booked: Martin