Real Madrid conceded more early ground in the La Liga title race as they could only salvaged a 0-0 draw with Racing Santander after winger Oscar Serrano came close to making it two successive defeats for Jose Mourinho's side.
A 1-0 weekend defeat by Levante was almost matched when Serrano's shot forced Iker Casillas into the best save of the match. Following a quiet opening, Racing threatened with a Papa Diop free-kick that floated into the box after 20 minutes, but Xabi Alonso got up well to head the chance out for a corner.
As the half-hour approached, Lassana Diarra tried a shot from long distance, but it was off target. Marcelo floated a cross into the Racing box as Madrid started to exert some control, but the ball was too high for Cristiano Ronaldo.
Marcelo then fired a low cross from the left across the Racing box, however, Jose Maria Callejon failed to get a touch despite lunging at the ball.
Ronaldo skewed a volley wide from a difficult angle and then sent a cross in for Callejon, who headed straight at Antonio Tono.
Serrano brought the game to life four minutes into the second half with a left-footed shot, forcing Casillas to dive low and turn it around the post. Gonzalo Higuain had a shot after cutting in from the right, but Tono tipped the effort over.
Ronaldo was stopped by Bernardo Espinosa's strong challenge, but hit his free-kick into the wall before Alonso fired the rebound wide.
Ronaldo then threaded a pass into the area to Karim Benzema, who was effectively bundled away from the ball. Marcelo then whipped in a cross for Ronaldo, but the striker just failed to get his head on the ball as another Real attack broke down.
And finally, the ball broke to Higuain, but he fired into the side netting cementing a frustrating night for the Madridistas.