Robert Lewandowski had a golden chance to open the scoring after four minutes, but put his effort onto the roof of the net.
Taty Castellanos also shot wide when through on goal for the visitors.
It is only the third time this season that Barcelona have dropped points at home.
But despite the disappointment of failing to win, Xavi’s side increased their advantage over Real Madrid to 13 points after their title rivals were beaten by Villarreal on Sunday.