Real Madrid's sixth straight LaLiga win took them six points clear at the top of the table on Saturday night.
Real coach Zinedine Zidane said: "Today we can only but happy with the three points, but we can't be happy with the performance. At times these things happen, you score two goals and are in the driving seat and then a goal changes the game. They went into the break looking brighter than us. There was a lot of rain out there and we showed less concentration and that's all there is to it. The game became a bit difficult for us.
"We've got reason to be happy because we're top, we keep up our good form and we have to continue on in this vein. It wasn't like a cup final for us but it was an important game and it was one we struggled to win. Sporting played well, but we didn't perform as we expected to. We'll continue to have tough games between now and the end of the season. Sides that are struggling in the league can make life difficult for you."