Leeds head coach Thomas Christiansen felt his side had been the architects of their own downfall.
Kenneth Zohore scored twice and Junior Hoilett added a beauty as Cardiff swept aside the Whites 3-1 to replace them at the league summit.
Leeds had skipper Liam Cooper sent off at the end of the first half before Kemar Roofe struck a consolation for the visitors.
“The two mistakes brought Cardiff into the game as they had not created any problems for us, and then the red card was very bad for us,” a disappointed Christiansen said after the match.
“There was a good response and good character and we played better with 10 men.
“I believe the team responded in the proper way from our defeat at Millwall and we are going to do the same against Sheffield Wednesday.”
On Cooper’s red card, Christiansen added: “The player that I was I know that these situations can happen.
“Of course, he is experienced in that situation and he should have known how the ball came.
“But I don’t want to blame anyone individually because we win and lose all together.”