"We were 2-0 up and had the game in the bag but a totally unprofessional five minutes finished us off," fumed the Charlton manager.
"I said to my players they have to learn from that because we managed to throw it away. They scored three in five minutes and that should not happen to anyone. This is a blow and a setback but if we can learn then we can take things forward."
Curbishley then turned pugilistic to explain his side’s collapse: "We went looking for a third goal and one or two of our players fancied scoring it.
"If we got behind the ball and dug it out for a while they would not have been in a position to score three goals in five minutes and 40 seconds. You have to give yourself a chance and we shouldn't have allowed the ball to come near our box for a couple of minutes.
"It's like a boxer getting knocked down, getting up on the count of two and throwing punches. We should have stayed down for a count of eight, got up with a clear head and then hit back."
Curbishley now hopes his players can now respond to the forthcoming Premiership challenges. "I don't want to be too negative because there have been some good performances this season, but at times we have to be more professional."
The last time Charlton collapsed in similar spectacular fashion was on Boxing Day, when they crashed 5-0 at West Ham. That defeat was the springboard for a six-match unbeaten run, and Curbishley now hopes for a similar positive response.
"This result is a blow and a setback, but if we can learn from it then we can move forward," he said. We got hurt badly at West Ham on Boxing Day but the response from the players was terrific after that, so I am hoping for more of the same.
"We fancied our chances against Spurs and the reward was another home tie. We are disappointed and the only consolation is that it was not a league game.
"We are a newly promoted side and our aim is to stay where we are - in the Premiership. We are in a decent position in the league and there are a lot of games left. We are only three points off fifth place and if the results go our way on Saturday, and then we get the right result against Newcastle on Sunday, we can push right into the top few.
"We took a few liberties against Spurs and got hurt. I have told my players that if they take liberties in the Premiership then they will also get hurt, no matter who they are playing against."
Alan Curbishley blamed the FA Cup defeat on an "unprofessional five-minute spell" from his players during which Spurs scored their first three goals.