Craig Bellamy scored a spectacular free-kick on his return from injury to set Cardiff City on their way to a third successive home victory.
Bellamy found the far top corner with a 20-yard drive three minutes after coming on as a second-half substitute.
Peter Whittingham's penalty doubled the lead after Nicky Maynard was bundled over by Leeds defender Tom Lees.
Leeds responded with Rodolph Austin's 30-yard free-kick before Tommy Smith was denied a late third for Cardiff.
Visiting goalkeeper Paddy Kenny saved low from Smith to ensure the home side were denied the comfortable end their second-half dominance had deserved.
After 45 minutes of what can generously be described as committed football by both sides, Heidar Helguson wasted the only scoring opportunity of the first half in stoppage time.
The forward was unmarked seven yards out but failed to keep his header under the crossbar from Whittingham's corner.
Cardiff dominance over Leeds
- Cardiff are now unbeaten in 14 league and cup matches against Leeds, having won nine and drawn five since a 1-0 away defeat in February 1984.
But Cardiff looked like a side transformed after the break.
Having been thwarted through the middle by Leeds' combative spoiler Austin, the home side began to find success down the flanks.
First Maynard forced an instinctive save from Kelly, before the goalkeeper was at full stretch to save Mark Hudson's far post header.
Craig Noone had played his part in Cardiff's period of ascendancy, but the winger was removed to allow for Bellamy's introduction.
The former Liverpool striker, recovered from a torn calf, had recently felt the need to release a statement denying rumours he was considering retiring from the game.
A huge ovation greeted Bellamy as he came off the bench on 64 minutes, and the home fans were soon on their feet again when his free-kick broke the deadlock.
Kenny had no chance as Bellamy's rasping drive from the left edge of the area flew in to give the 33-year-old his first goal of the season.
The ever-dependable Whittingham then put Cardiff firmly in control when he sent Kenny the wrong way from spot after a clumsy Lees challenge brought down Maynard in the area.
Leeds had offered nothing after the break, but they sensed an unlikely draw when Austin's 30-yard free-kick beat David Marshall.
The Cardiff goalkeeper berated his wall, but Austin's low drive was only a yard from the middle of the goal as it went in.
Kenny kept Leeds in sight of a point with two more fine saves, denying Maynard from six yards and then dropping to the ground quickly as Smith fired from 18 yards through a crowded area.
But Cardiff were lucky to escape four minutes from time when a Lee Peltier header sailed a yard over the bar with Marshall beaten.
Cardiff City manager Malky Mackay:
"We spoke at half-time, upped the tempo and attacked them in different areas in the second half.
"We had 19 chances at goal and Paddy Kenny made three or four magnificent saves. On another day we could have scored four or five.
"After half-time we looked a different team. It's early days in the division, but I'm delighted with the win."
Leeds United manager Neil Warnock:
"I thought we deserved a point. But to lose Ross McCormack after three minutes was hard, he's our only Bellamy.
"Ross has twisted his ankle quite severely. I don't think there is any break, but we can't tell yet because of the swelling. I'd imagine he'll be out for a few weeks.
"It was a fantastic goal by Bellamy, but we were very disappointed with the free-kick that was given."
Live Text Commentary
Full Time The final whistle is blown by the referee.90:00 +3:42
Luciano Becchio gives away a free kick for an unfair challenge on Don Cowie. Free kick taken by David Marshall.90:00 +2:39
El-Hadji Diouf challenges Mark Hudson unfairly and gives away a free kick. David Marshall takes the direct free kick.87:47
Michael Tonge fouled by Aron Gunnarsson, the ref awards a free kick. Direct free kick taken by Patrick Kenny.86:32
Lee Peltier produces a header from inside the area that goes over the crossbar.85:25
Effort from 18 yards by Tommy Smith. Blocked by Patrick Kenny.84:16
Free kick awarded for an unfair challenge on Tommy Smith by Lee Peltier. The free kick is swung in left-footed by Peter Whittingham.83:34
The official flags Luciano Becchio offside. Andrew Taylor takes the indirect free kick.82:55 Substitution
Substitution Luke Varney leaves the field to be replaced by Dominic Poleon.82:04 Substitution
Substitution Don Cowie on for Nicky Maynard.78:48
Inswinging corner taken by Craig Bellamy.78:25
Nicky Maynard takes a shot. Jason Pearce gets a block in.76:41 Goal scored
Goal! - Rodolph Austin - Cardiff 2 - 1 Leeds Rodolph Austin scores a goal direct from the free kick from long range to the bottom right corner of the goal. Cardiff 2-1 Leeds.76:08
Aron Gunnarsson challenges Luke Varney unfairly and gives away a free kick.75:22 Substitution
Substitution Jordon Mutch leaves the field to be replaced by Aron Gunnarsson.72:02 Goal scored
Goal! - Peter Whittingham - Cardiff 2 - 0 Leeds Peter Whittingham scores a placed penalty. Cardiff 2-0 Leeds.71:07
Tom Lees gives away a Penalty for an unfair challenge on Nicky Maynard.66:54 Goal scored
Goal! - Craig Bellamy - Cardiff 1 - 0 Leeds Craig Bellamy grabs a goal direct from the free kick from just outside the box to the top left corner of the goal. Cardiff 1-0 Leeds.66:15 Booking
Booking The referee cautions Michael Tonge for unsporting behaviour.65:54
Michael Tonge challenges Nicky Maynard unfairly and gives away a free kick.
Mark Hudson takes a shot. Save by Patrick Kenny.64:26
Peter Whittingham decides to take the corner short.63:28 Substitution
Substitution Craig Noone leaves the field to be replaced by Craig Bellamy.63:01
Tommy Smith produces a left-footed shot from inside the six-yard box that clears the bar.59:24
Andrew Taylor delivers the ball.58:40
The offside flag is raised against El-Hadji Diouf. David Marshall takes the free kick.58:27
The assistant referee flags for offside against Nicky Maynard. Free kick taken by Patrick Kenny.57:50
Tommy Smith takes a shot. Save by Patrick Kenny.57:03
Free kick awarded for an unfair challenge on Aidan White by Craig Noone. Patrick Kenny takes the free kick.56:33
Handball by Luciano Becchio. David Marshall takes the direct free kick.54:07
Shot from just outside the box by Peter Whittingham misses to the left of the goal.53:09
The assistant referee signals for offside against Lee Peltier. Indirect free kick taken by David Marshall.49:10
Jordon Mutch produces a right-footed shot from just outside the area that goes wide left of the goal.47:39
Nicky Maynard takes a shot. Save by Patrick Kenny.46:04
Effort from the edge of the area by Craig Noone goes wide of the left-hand upright.45:26
Unfair challenge on Samuel Byram by Peter Whittingham results in a free kick. Tom Lees restarts play with the free kick.45:01
The referee starts the second half.45:01 Substitution
Substitution El-Hadji Diouf joins the action as a substitute, replacing Adam Drury.45:00 +3:05 Half time
Half Time The whistle is blown to end the first half.45:00 +0:52
Outswinging corner taken left-footed by Peter Whittingham from the left by-line, Heidar Helguson produces a header from inside the area that goes over the bar.45:00 +0:29
Short corner taken by Peter Whittingham.44:56
Tommy Smith produces a cross, save by Patrick Kenny.44:21
Jordon Mutch takes a shot. Tom Lees gets a block in.43:31
Nicky Maynard takes a shot. Rodolph Austin gets a block in.39:29
Free kick awarded for a foul by Michael Tonge on Nicky Maynard. Free kick taken by Peter Whittingham.38:18
Direct free kick taken by Patrick Kenny.38:18 Booking
Booking Booking for Tommy Smith for unsporting behaviour.38:04
Foul by Tommy Smith on Samuel Byram, free kick awarded.37:06
Andrew Taylor restarts play with the free kick.37:06 Booking
Booking Booking for Rodolph Austin.36:50
Foul by Rodolph Austin on Nicky Maynard, free kick awarded.34:38
Jordon Mutch gives away a free kick for an unfair challenge on Lee Peltier. Patrick Kenny takes the direct free kick.31:56
Luke Varney is ruled offside. David Marshall takes the indirect free kick.30:08
Effort from outside the area by Jordon Mutch goes wide right of the goal.27:29
Heidar Helguson takes a shot. Patrick Kenny makes a comfortable save.26:49
A cross is delivered by Tommy Smith, save made by Patrick Kenny.26:02
Unfair challenge on Nicky Maynard by Rodolph Austin results in a free kick. Free kick taken by Kevin McNaughton.23:37
Andrew Taylor concedes a free kick for a foul on Samuel Byram. Michael Tonge delivers the ball, Close range headed effort by Rodolph Austin misses to the right of the goal.22:01
Samuel Byram is flagged offside by the assistant referee. David Marshall takes the free kick.21:28
Foul by Nicky Maynard on Rodolph Austin, free kick awarded. The free kick is delivered left-footed by Adam Drury from left channel.20:57
Nicky Maynard takes a shot.20:18
Luciano Becchio challenges Mark Hudson unfairly and gives away a free kick. David Marshall takes the direct free kick.19:43
Foul by Matthew Connolly on Luke Varney, free kick awarded. Direct free kick taken by Patrick Kenny.18:56
Craig Noone takes a shot. Lee Peltier gets a block in.15:56
Peter Whittingham fouled by Luciano Becchio, the ref awards a free kick. Direct free kick taken by Peter Whittingham.12:33
Samuel Byram takes a shot. Save made by David Marshall.11:52
Luke Varney takes a shot. Blocked by Kevin McNaughton.10:02
Handball by Nicky Maynard. Adam Drury takes the direct free kick.8:34
Inswinging corner taken from the right by-line by Peter Whittingham.8:02
Craig Noone delivers the ball, clearance by Tom Lees.7:03
Free kick awarded for a foul by Jordon Mutch on Aidan White. Adam Drury takes the free kick.4:57 Substitution
Substitution Luke Varney comes on in place of Ross McCormack.2:01
Nicky Maynard is ruled offside. Patrick Kenny takes the free kick.0:00
The referee gets the game started.
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