Real Madrid lead Athletic Bilbao by one goal to nil thanks to Karim Benzema's strike in a game which has seen plenty of chances for both sides.
Raul Garcia created the first chance of the game, releasing Aritz Aduriz in the box but Raphael Varane's pace allowed the defender to clear the danger before the striker could get a shot away.
Real Madrid counter-attacked through Cristiano Ronaldo, whose left-wing cross was taken off the head of Isco by Karim Benzema.
Benzema was the player who opened the scoring after 19 minutes as he pounced on a misplaced Mikel San Jose backpass and finished past Gorka Iraizoz in the Bilbao goal.
The French striker then missed a chance to double his tally and Madrid's lead, failing to connect with a Marcelo cross.
Ronaldo then set Isco free, the Spanish midfielder teeing up Toni Kroos in the box, but the German international dragged his effort wide of the target.
A flurry of chances towards the end of the half saw Keylor Navas deny Aduriz's diving header before Iraizoz kept out a point-blank strike from Mateo Kovacic.
