Madrid needed Francisco "Isco" Alarcon to come off the bench and score three minutes later in the 64th to salvage a point from the visit to the Basque Country club. Isco slipped into the area unmarked and headed Gareth Bale's cross down off the turf and into the corner of the net.

Bilbao went ahead in the 32nd when right back Oscar de Marcos made a run into the area, and squared the ball for Inaki Williams to finish off. Iker Muniain took the goal when he tapped in Williams' shot that was about to cross the goal-line.

Bilbao avoided giving Madrid chances to counterattack with long balls forward to Williams, and did well to pressure the visitors when they tried to go forward with passing buildups.

Before Isco's equalizer, Madrid was limited to an excellent chance by Sergio Ramos after Bilbao goalkeeper Unai Simon fumbled a free kick by Bale into the defender's path, only to also save Ramos' point-blank attempt.

Muniain had to be substituted early in the second half for what appeared to be a non-serious leg injury.

"We knew this was one of the toughest grounds to visit in the league," Ramos said. "We needed to circulate the ball more quickly, but they defended us very closely and worked well as a group. A draw is never good."

Madrid won in the first three rounds under new coach Julen Lopetegui. It trails defending champion Barcelona by two points at the top of the table.

Madid hosts Roma in their Champions League opener on Wednesday.