Despite running out 3-0 winners, Barcelona spent much of Wednesday's second leg on the back foot as Real Madrid spurned chance after chance.
"It's been one of the games at the Bernabeu in which we have suffered the most and had least possession of the ball," said Busquets after the match, which had been a bizarre affair. Both teams had switched from their traditional identities, with Madrid dominating possession while Barcelona were more threatening and clinical on the break.
And this was a fact Busquets was quick to acknowledge. "They were better in possession, we had to stay together and counter where we could. But they missed their chances and when you do that, you're going to get punished."
"To play here is the ultimate challenge, but the performance of the team has been amazing - we can't have asked for more from ourselves in terms of the cup recently."
Having making his delight at the result clear, Busquets looked to the future, starting on Saturday with another clash with Real Madrid in La Liga. "On a psychological level we will be ready, but when they [Madrid] start to pass the ball about things can change. It becomes a totally different situation."
They have a Champions League match on the following Tuesday, but that doesn't affect us. We have to be prepared for what will be a very important match in La Liga.