Match ends, Cardiff City 0, Leeds United 2.
Leeds claimed a precious win at Cardiff City to ease the pressure on manager Garry Monk and intensify scrutiny over the future of Bluebirds boss Paul Trollope.
Cardiff hit the post twice as they shaded a goalless first half but Leeds struck against the run of play, Chris Wood scoring with a penalty.
Ex-Swansea winger Pablo Hernandez sealed victory late on.
A fourth straight defeat keeps Cardiff in the Championship relegation zone.
Even at this early stage in the season, this was a crucial match for two managers whose tenures already looked under threat.
While former Swansea manager Monk had earned a reprieve at Leeds with a midweek win over Blackburn - only their second of the season -Trollope had overseen three successive Cardiff defeats before this damaging fourth.
In an attempt to arrest that slide, he abandoned his favoured 5-3-2 formation and plumped for 4-3-3, which helped the Bluebirds play with more urgency than in recent games.
Captain Sean Morrison's header hit the post as the hosts started strongly, but Leeds threatened on the break with Hernandez and Wood both forcing Ben Amos into good saves.
Iceland international Aron Gunnarsson's low shot struck a post shortly before half-time as Cardiff continued to press, but their inability to convert pressure into goals proved costly.
Leeds were awarded a penalty when Matt Connolly wrestled Pontus Jansson to the ground from a corner, and Wood sent Amos the wrong way with a coolly taken spot-kick.
Hernandez put the result beyond doubt as he found the top corner with a fine whipped effort, the former Swan putting Trollope's future as Cardiff head coach in grave doubt.
Cardiff City manager Paul Trollope:
"I thought we were in pretty good control, we needed one of the chances to go in and they didn't.
"The refereeing decision changed the game, which was frustrating for us because there was a lot going on at set-pieces at both ends.
"I'm not saying it wasn't a penalty but if he's giving it then he could be giving a few at either end."
Leeds United head coach Garry Monk:
"We have a new group, new manager, new ideas, and we are taking it step by step.
"We are right at the start of that journey and if we give this group time to show their quality they can potentially grow into something very good.
"This is another step in the right direction. We are getting there slowly, we've not yet had that complete performance but we are growing.
"It was important to get those back-to-back wins and see how these young players deal with that momentum."
- 16ConnollySubstituted forGounongbeat 83'minutes
- 8RallsSubstituted forK Harrisat 70'minutes
- 13PilkingtonSubstituted forImmersat 88'minutes
- 5Ecuele Manga
- 24K Harris
- 2AylingBooked at 42mins
- 24SackoBooked at 27mins
- 19HernándezSubstituted forPhillipsat 89'minutes
- 15DallasBooked at 54minsSubstituted forRoofeat 71'minutes
- 9WoodSubstituted forAntonssonat 90+2'minutes
- Graham Scott
- Shots on Target
Second Half ends, Cardiff City 0, Leeds United 2.
Attempt blocked. Hadi Sacko (Leeds United) left footed shot from the centre of the box is blocked. Assisted by Kemar Roofe.
Attempt missed. Craig Noone (Cardiff City) left footed shot from outside the box is high and wide to the left. Assisted by Peter Whittingham.
Substitution, Leeds United. Marcus Antonsson replaces Chris Wood.
Hadi Sacko (Leeds United) wins a free kick on the right wing.
Foul by Lex Immers (Cardiff City).
Offside, Leeds United. Eunan O'Kane tries a through ball, but Chris Wood is caught offside.
Substitution, Leeds United. Kalvin Phillips replaces Pablo Hernández.
Substitution, Cardiff City. Lex Immers replaces Anthony Pilkington.
Foul by Kemar Roofe (Leeds United).
Kadeem Harris (Cardiff City) wins a free kick on the right wing.
Attempt saved. Rickie Lambert (Cardiff City) header from the centre of the box is saved in the bottom left corner. Assisted by Peter Whittingham with a cross.
Corner, Cardiff City. Conceded by Ronaldo Vieira.
Substitution, Cardiff City. Frederic Gounongbe replaces Matthew Connolly.
Goal! Cardiff City 0, Leeds United 2. Pablo Hernández (Leeds United) right footed shot from the left side of the box to the top right corner.
Attempt missed. Kyle Bartley (Leeds United) header from the centre of the box is high and wide to the right. Assisted by Pablo Hernández with a cross following a corner.
Corner, Leeds United. Conceded by Ben Amos.
Attempt saved. Hadi Sacko (Leeds United) right footed shot from the right side of the box is saved in the bottom right corner. Assisted by Pablo Hernández.
Attempt saved. Pablo Hernández (Leeds United) right footed shot from outside the box is saved in the bottom right corner. Assisted by Kyle Bartley.