City's Development side won away at Crystal Palace on Tuesday night with Filip Kiss scoring a penalty to bring City level after going a goal down.
Rhys Healey's header won it for Cardiff against a Palace side that contained former Bluebird Neil Alexander in goal.
There was no Etien Velikonja in the Cardiff squad.
Cardiff: Moore, Yorwerth, Owen, Kiss, Oshilaja, Williams, O'Sullivan, Mutch, Mason, Healey, Harris.
subs: Matthews (GK), Roche, Southam, Bowen, Wharton.
Palace: Alexander, Taylor, Parr, Dymond, McCarthy, Wynter, De Silva, Boateng, Sekajja, Grandin, Kaikai.
Subs: Croll, Fitzsimons, Gordon, Sow, Allassani