Goals early each half gave Burnley victory, easing their relegation concerns and denting Cardiff's hopes of reaching the Championship play-offs.
Steve Jones' drive inside the box put the Clarets ahead on four minutes, Andy Gray then hitting the crossbar.
Roger Johnson had an effort cleared off Burnley's line, but the home side took control when Paul McVeigh converted Wade Elliott's cross on 48 minutes.
Johnson then had a goal ruled out for offside in the closing stages.
Burnley boss Steve Cotterill:
"We are delighted with the clean sheets - you can't beat them.
"Wayne Thomas has been absolutely first-class recently and I'm delighted for him.
"I think Michael Duff and Jon Harley have also been superb at full-back and Steve Caldwell has been a rock since his came here."
Cardiff boss Dave Jones:
"I thought we started brightly but sloppiness, laziness, whatever you want to call it, cost us.
"I can't remember my goalkeeper having anything to do in the first half apart from picking the ball out of the net and that's down to sloppy defending.
"In the second half we didn't create enough chances and the second goal was a poor one to give away."
Burnley: Jensen, Duff, Thomas, Caldwell, Harley, Elliott (Akinbiyi 87), Djemba-Djemba, James O'Connor, Jones, McVeigh (McCann 76), Gray (Spicer 90).
Subs Not Used: Coyne, Coughlan.
Booked: Jones, Gray, Harley, Thomas, Elliott.
Goals: Jones 4, McVeigh 48.
Cardiff: Forde, McNaughton, Purse, Johnson, Ledley, Whittingham (Thompson 73), McPhail, Gunter, Parry (Blake 68), Chopra, Feeney (Green 56).
Subs Not Used: Alexander, Flood.
Ref: R Beeby (Northamptonshire).