KENNETH ZOHORE ended his eight-match goal drought to send Cardiff top.
The giant striker had not scored since the opening day of the Championships season at Burton.
But he bagged a brace against 10-man Leeds to keep alive City’s promotion dream.
Junior Hoilett struck between Zohore’s double to complete a miserable night for more than 3,000 travelling fans.
Little wonder that City boss Neil Warnock punched the air with delight when the final whistle blew.
It was a job well and truly well done by the high-flying Bluebirds.
Hundreds of fans were still streaming into the stadium 10 minutes after kick-off.
It was a tense affair on and off the field. Both sets of fans were in great voice.
Cardiff had the better of the early play with Loic Damour’s fifth minute strike drifting wide.
Leeds defender Pontus Jansson underwent lengthy treatment following a clash in the Leeds’ box.
The 26-year-old Swede was soon up and running and directing his troops as they came under siege.
The visitors were falling like flies. Stuart Dallas was the next to go down after clashing with Lee Peltier.
There was precious little to write home about until Joe Bennett’s 20 yarder was deflected over.
From the 12th minute corner Bruno Manga saw his goal-bound header diverted for another corner.
Leeds were barely recognisable from the side that lost only one of its opening 10 league games.
Boss Thomas Christiansen made five changes from the side that beat Ipswich 3-2 on Saturday.
One of Saturday’s survivors, Kalvin Phillips, was in a spot of bother at the end of the first quarter.
The midfielder was shown the yellow card for hacking down Junior Hoilett.
There was further trouble for United in the 28th minute as Cardiff struck a major blow.
Hoilett’s mazy run left a trail of white shirts in his wake.
When he pulled the ball back Zohore was on hand to convert from five yards.
It was the striker’s first goal since the opening day of the Championship campaign.
The Bluebirds’ fans taunted their rivals with chants of ‘We are top of the league’, It took Leeds 35 minute to fashion a chance of real note.
Sadly Pablo Hernandez miscued his free kick and the chance went begging.
There was nothing left to chance 30 seconds later as City doubled their lead in spectacular fashion.
Hoilett picked up the ball 30 yards from goal and after two touches smashed it past the despairing lunge of Felix Wiedwald.
It couldn’t have got any worse for United. Or could it? It certainly did with Liam Cooper being shown two yellow cards in the space of six minutes.
Both were for dreadful tackles on Cardiff flier Nathaniel Mendez-Laing.
Eight minutes into the second half Leeds had three wonderful chances to get themselves back into the game.
Neil Etheridge saved at the feet of Gaetano Berardi.
From the rebound the City keeper kicked away Ezgjan Alioski’s 25 yarder.
When the ball came back into the box, Dallas wide with a header from six yards.
A minute later Kemar Roofe fired into the arms of Etheridge from a dozen yards.
Once again, Leeds were made to pay the ultimate price.
Cardiff pushed forward and when Mendez-Laing delivered from the right, Zohore was on hand to score from barely a yard.
Leeds grabbed a lifeline in the 67th minute when a slick move saw Roofe’s deflected shot beat Etheridge.
Cardiff were becoming edgy and Sol Bamba started to read the riot act to his fellow players.
To their credit Leeds never stopped running. They were better with 10 than they had been with 11.
Christiansen roared them forward in the final 15 minutes.
But they lacked penetration in the final third and Cardiff held on to another vital victory.