The La Liga leaders missed the chance to move seven points clear at the summit in a game dominated by controversy over the refereeing
Ernesto Valverde felt Barcelona were hurt by an "invisible penalty" after they let slip a first-half lead to draw 1-1 at lowly Las Palmas.
The LaLiga leaders appeared on course to restore their seven-point cushion over Atletico Madrid at the top of the table thanks to Lionel Messi's 21st-minute free-kick.
However, the hosts were gifted the chance to equalise straight after the break when referee Antonio Mateu pointed to the spot for an apparent infringement at a corner.