Mark Hudson made nine changes due to Cardiff’s squad being hit by a sickness bug, while Jesse Marsch made seven alterations to the Leeds side that drew against West Ham United.
Incoming 18-year-old midfielder Darko Gyabi impressed in the early stages of his second senior start but couldn’t quite force an opener, striking one shot agonisingly wide before Jack Simpson blocked another.
Crysencio Summerville then wasted a brilliant opportunity after Tom Sang had failed to clear Wilfried Gnonto’s cross.
The more regular starter, Pascal Struijk, wasn’t looking quite as confident as Gyabi and Mark Harris capitalised on that.
The Welshman raced behind Struijk to reach Sang’s through ball and kept the move alive for Jaden Philogene to convert.
Cardiff hadn’t scored in their previous four matches, but had two goals in seven minutes as Diego Llorente couldn’t get enough on Andy Rinomhota’s pass to stop it from reaching Sheyi Ojo, who chested it and fired home.
At the other end, Gnonto missed a headed chance, and Jak Alnwick came out sharply to deny Brenden Aaronson before HT.
Having seen no significant improvement by the hour mark, Marsch resorted to bringing on Rodrigo Moreno, debutant Maximilian Wöber, and Cody Drameh, with Wöber immediately being denied by Rinomhota’s emphatic block.
After Struijk wasted a headed opportunity from a Sam Greenwood cross, Rodrigo showed him how it’s done by steering the ball past Alnwick despite the goalkeeper getting a hand on it.
With the Leeds pressure building, Joel Bagan saw red for handling Junior Firpo’s goalbound shot in the 80th minute, but Alnwick was equal to Rodrigo’s powerful penalty.
However, the Whites refused to give up and Perkins prodded the ball past Alnwick in the 94th minute for his first senior goal to force a replay, giving Leeds hope of making it past this stage of the FAC for the first time in six seasons.
Meanwhile, Cardiff have still not beaten a Premier League side in this competition since 2014.
