Town got off to the perfect start under new boss Roy Keane with goals from Pablo Counago, David Norris and Jon Stead spoiling the party for Cardiff.
The Bluebirds were making a last League appearance at Ninian Park before moving into their new stadium for next season and the home fans were in celebration mood before kick-off.
Ross McCormack had a gilt edged chance to give Dave Jones' side the edge early on but saw his penalty saved superbly by Richard Wright and Town never looked back from there.
Counago's 10th goal of the season put Blues ahead 10 minutes before the break and Norris' expert finish early in the second-half extended the lead, with Stead on target seconds from the end after Ivan Campo's free-kick had hit the post.
The new Town boss made three changes from the team that beat Norwich last week, Jaime Peters coming in for his first start this season and Matt Richards his first appearance in two years with Owen Garvan starting.
Cardiff, not surprisingly, started brightly in their final League game at Ninian Park and Joe Ledley volleyed wide, then Jay Bothroyd had a header over before the Bluebirds were handed a penalty on 12 minutes. Ivan Campo judged to have pushed Roger Johnson as he attacked a Kevin McNaughton free-kick. Wright came to Town's rescue though with a fantastic save diving to his right to deny McCormack's strike.
Peters was prominent for Blues in an attacking right-back role and led a counter attack that saw McNaughton pull him to the ground, Giovani's free-kick failing to trouble Heaton in the Cardiff goal.
Counago almost got on the end of Peters' cross after more good work by the Canadian international, while at the other end Bothroyd was blocked out.
Town were forced to make a change just before the half hour mark with Alex Bruce suffering a thumb injury with Stead the replacement, Campo dropping from his holding midfield role to partner Pim Balkestein in the middle of the defence.
Stead made an immediate impact, getting on the end of a ball over the top and finding Counago who fired into the roof of the net to give Town the lead on 34 minutes.
Bothroyd was inches away from getting on the end of Mark Kennedy's cross as Cardiff looked to rally, McCormack finding no way past Campo as Blues maintained the lead to the break.
Counago had the first effort of the second-half, his shot saved by Heaton but the Manchester United loanee had no chance on 50 minutes, Peters and Stead again involved and Norris buried a drive past the 'keeper.
Chris Burke pushed Wright into action before Town made a second change, Counago making way for Danny Haynes while Cardiff introduced Stephen McPhail and Michael Chopra for Paul Parry and McCormack.
Richards produced a great tackle to deny Chopra announcing his arrival on the game with a goal, Giovani then showing good touch and pace to weave away from Gavin Rae before seeing his shot blocked by Gabor Gyepes.
Wright held firm at the nearpost as Bothroyd threatened before Blues made a final change, Peters - who was suffering with cramp - bowing out with Alan Quinn his replacement, Norris moving to right-back.
Quinn and Giovani just failed to get on the end of Haynes' cross, Cardiff then making a final change with Eddie Johnson replacing Rae for the last 15 minutes.
Giovani was booked by referee Scott Mathieson for kicking the ball away, Haynes following seconds later for a foul on Ledley.
Wright saved brilliantly again from Eddie Johnson. Gyepes was cautioned for a foul on Giovani on the edge of the box as the game entered added on time and Blues made Cardiff pay, Campo's free-kick hitting the post and Stead forcing the ball in from close range to take his goal tally to 13 for the season and Town to nine away wins for the term.
Cardiff have the consolation of the Play-Offs to face while Town could not have started the Keane era in better fashion.
Cardiff: Heaton, McNaughton, Gyepes, R.Johnson, Kennedy, Rae (E.Johnson 75), Parry (McPhail 57), Ledley, Burke, Bothroyd, McCormack (Chopra 57). Subs not used: Comminges, Purse. Booked: McNaughton, Gyepes.
Town: R.Wright, Peters (Quinn 72), Bruce (Stead 29), Balkestein, Richards, Campo, Norris, Garvan, Lisbie, Giovani, Counago (Haynes 56). Subs not used: Bialkowski, Miller. Booked: Giovani, Haynes.
