Real Madrid extended their lead at the top of La Liga to five points with a narrow win against Athletic Bilbao at the San Mames Stadium.
Second-placed Barcelona, who have played the same amount of games as Real, host Valencia on Sunday.
Real, who are chasing their first league title since 2011-12, went ahead through Karim Benzema on 25 minutes.
Veteran striker Aritz Aduriz equalised on 65 minutes, before Casemiro scored the winner three minutes later.
Barcelona can cut the gap back to two points when they face Valencia at the Camp Nou on Sunday.
Athletic were undefeated in 19 games at home in all competitions stretching back to August and started confidently with Inigo Lekue threatening early down the left.