Gaetano Berardi was sent off as Leeds slipped to a 4-1 home defeat to Cardiff.
Three first-half goals from Callum Paterson, Junior Hoilett and Sean Morrison did the damage at Elland Road as the on-song Bluebirds continued their quest for automatic promotion from the Sky Bet Championship.
Souleymane Bamba put through his own net to get the hosts on the board after the break, but Thomas Christiansen's side struggled to mount a serious comeback after going down to 10 men and Anthony Pilkington wrapped things up with a fourth goal two minutes from time.
The result was Cardiff's third straight win against Leeds, and meant they extended their undefeated league run to five games after four successive defeats.
Leeds, on the other hand, have gone seven games without a win in all competitions, with their last victory coming on Boxing Day.
It was Berardi's second red card of the season, with five of his six career dismissals coming since the Swiss defender joined Leeds in 2014.