Barcelona midfielder Andres Iniesta has branded Sunday's 4-1 win over Sevilla as "important".
Results on Saturday dropped the Catalan outfit into third spot in the table, but they returned to the summit with all three points at the Estadio Ramon.
"It was important to go top again. The circumstances perhaps weren't the best but in the end we won the match," he told reporters.
"When you have a chance, you have to take advantage of it. I think this victory will give us strength ahead of the match on Wednesday and for the games to come after that.
"[Lionel] Messi always responds. He never misses and in just a few minutes he can change a game. He's a fundamental player. We will fight until the end. The important thing is to not lose a lot of points and to improve as a team."
Barcelona, Real Madrid and Atletico Madrid all have 57 points after 23 matches.
