Cardiff manager Dave Jones hailed his team's fighting qualities in what he called a "proper Cup tie."
After seeing his men battle back from 2-1 down to claim a place in the fifth round with two goals in time added on, Dave said: "We hung in there and that was the most important thing. Then we got a break and a bit of luck along the way.
"Whitts' goal from the free kick gave us a break and then there was another half a yard in our stride. That's confidence for you.
"We get our noses in front, the crowd are up and that's it, a proper cup tie. Dave makes a good save and we go up the other end and we kill them. That's what football in the Cup is all about."
Dave revealed that Chris Burke, who came off the subs' bench to fire Cardiff 3-2 ahead in time added on, was struggling with a rib injury.
"He was white, and I was hoping to get away without using him. Mark Kennedy at left back came on the other night for his first 20 minutes' football in a month. I asked him today did he want to come off and he said no, he wanted to stay on. Quinny was passed fit only this morning.
"My problem is they keep winning and getting results and everybody thinks everything is OK but it's not. The club is prime for a takeover and that will be the final piece of the jigsaw to enable us to push on. Without that, I don't know. On my side of the business, we need a little bit of help. When we get the green light, and hopefully that's pretty soon, this club will fly.
"Everybody's been hit by a virus, and nobody in the camp has been feeling 100 per cent but we get two victories, so there's a lesson for everyone. Just hang in there and hope you get a break.
"At 2-1 down, I couldn't see us passing or getting any movement. We looked a little bit jaded and down, and confidence was starting to go. It was the same for Leicester, because until we got the equaliser they were dominant.
"Nigel Pearson will be a bit sickened because when they got in front they were in charge of the game. At 2-2, I turned round to Terry Burton and said the last thing I need is a replay. Nigel felt the same. I'm going to see him again in the league and I'm seeing Gary Johnson next week for the fourth time this month, if you include the game that was called off.
"I'm seeing too much of these guys - my wife will be thinking there's something going on between me and Gary! That's why in the next round I want to be at home - but not to someone in our division!"
Dave also paid tribute to the fans who got behind the Bluebirds as they clinched a place in Sunday's fifth round draw. He said: "The crowd, the majority of them, stuck with us, and kept going with us. People at the moment are counting the pennies and we are grateful to the fans who turned up today.
"We know it's difficult. We had a game on Tuesday, we've got another game this coming Tuesday, we go on Saturday again, then a Friday then a Tuesday. It's a lot of money for people to keep finding, an awful lot. People who came here today deserve a big slap on the back because the FA Cup is an extra cost, it's not part of your season ticket and it's a lot of money. It's difficult at the moment to keep finding that money, and we acknowledge that."
