Cristiano Ronaldo grabbed the winner, seconds after Barca substitute Alexis Sanchez had cancelled out Sami Khedira’s opener.
The win moved Jose Mourinho’s men seven points clear of Barca with just four games remaining as Los Merengues closed in on their first La Liga title since 2008.
“We played as a team,” goalkeeper Casillas told www.realmadrid.com.
“Cristiano did a fine job but all 11 did well. We played well as a team from the beginning.
“We worked well from start to finish although we suffered when they equalised.
“But we responded and got the win.”
The title race appears all but over with Casillas confirming:
“Although there are still points at stake and we must be respectful, we have taken a giant step.”