Leeds claimed a second successive league win to ease the pressure on manager Garry Monk and keep Cardiff in the bottom three of the Sky Bet Championship.
Chris Wood's fourth goal in six games, a 62nd-minute penalty rolled home in confident fashion, and Pablo Hernandez's first Leeds goal eight minutes from time secured a well-merited 2-0 success.
The three points moves Leeds towards the heady heights of mid-table after a fraught start to the season, Monk now having won four of his past six games in all competitions.
Cardiff's campaign, however, is showing little sign of flickering into life with only one victory all season and manager Paul Trollope struggling to cope with the expectations at a club who were in the Premier League three seasons ago.
Former Swansea boss Monk was returning to south Wales for the first time since his departure from the Liberty Stadium last December.
Having seen Cardiff strike the post twice in the first half, it eventually proved an enjoyable experience for Monk after Matthew Connolly grappled with Pontus Jansson in the penalty box and Hernandez showed his finishing skills honed on the pitches of LaLiga.
Cardiff had dropped into the relegation zone after a midweek beating at Preston and Trollope's response was to change both personnel and formation.
Out went a three-man central defence and wing-backs in favour of 4-3-3, and Cardiff certainly looked more balanced as Peter Whittingham and Craig Noone, both recalled amid five changes, posed problems with crosses.
Whittingham's dead-ball delivery was of particular concern, and Sean Morrison met his 15th-minute corner to strike the outside of a post with a firm header.
Former England striker Rickie Lambert marked his home debut with some impressive hold-up play, but Cardiff were unable to get him into scoring positions.
Leeds could count on the pace of Hadi Sacko on the break, but their best first-half moments came from Cardiff mistakes.
Connolly's poor pass allowed Hernandez to test the debut-making Ben Amos with a fierce drive before a Whittingham error set Leeds free again.
Sacko and Hernandez combined well for Wood to fire straight at Amos, with Whittingham doing well to atone for his original mistake by taking the sting out of the shot.
Cardiff almost took the lead two minutes before half-time when Leeds again struggled to clear their lines from a Whittingham corner.
Joe Ralls saw his shot blocked before Aron Gunnarsson's follow-up flew through pile of bodies and struck the woodwork.
But it was Leeds who provided the second-half attacking threat before Wood's calm finish.
Amos saved well from Sacko and Hernandez wrapped up the points with a delightful shot from the edge of the area.