Barca bounced back from their shock Champions League defeat at home to Rubin Kazan to thrash Real and extend their lead at the top of the Liga table.
"We've shown that we are physically strong and that we are capable of scoring goals. This success has been good for us, we are leaders with another three points. People tend to be result-focused but we know that things are going well," said Xavi.
"On Tuesday (against Rubin Kazan) we played well but failed to test their goal. Today we played more quietly and soon we were 2-0 ahead."