Barcelona regained the lead in La Liga, with a 1-0 win over their guest Rayo Vallecano, on Monday evening, in the 24th round, at the "Luis Companys Olympic" stadium.
The Blaugrana's only goal was scored by Robert Lewandowski, from a penalty kick in the 28th minute.
With this victory, Barcelona raised its score to 51 points at the top of La Liga, the same number of points as runner-up Real Madrid, who are behind their rivals due to the difference in direct confrontations.
In contrast, Rayo Vallecano froze at 35 points, in sixth place.
The match began with pressure from the home team, as Lewandowski received a cross from his teammate Rafinha, and shot over goalkeeper Batalla's goal in the 3rd minute.
Vallecano player, Khaled Abdelmoumen, was pulled by Blaugrana defender, Hector Fort.. but the referee refused to award a penalty kick to the guests, in a decision that sparked a refereeing controversy.
Pedri passed a magical pass deep in Vallecano's defense, which reached Rafinha who received it and shot, but goalkeeper Batalla saved it, before the ball hit the defense and reached the goalkeeper's arms, in the 23rd minute.
The referee decided to award a penalty kick in favor of Barcelona, due to Vallecano defender Paty Cisse bringing down his counterpart from the Catalan team, Inigo Martinez.
Lewandowski took the penalty kick, and succeeded in shooting to the bottom right of the goalkeeper, giving the Blaugrana the lead in the 28th minute.
Jorge de Frutos scored a goal for Rayo Vallecano, in the 43rd minute, but the referee canceled it due to offside.
At the start of the second half, Pedri passed the ball to Lewandowski, who shot wide of the goal.
Rafinha demanded a penalty kick, after a clash with Vallecano player Ratio, in the 62nd minute, but the referee indicated to continue playing.
Barcelona goalkeeper Wojciech Szczesny excelled in stopping a shot from De Frutos, as he caught it twice in the 66th minute.
Rafinha wasted a chance to add a second goal in the 72nd minute, when he received a through pass from Olmo to be alone with the goalkeeper, but he shot over the goal.
De Frutos almost snatched the equalizer for Vallecano, when he received a cross from the left side, and headed it over Szczesny's goal in the 90th minute.
Barcelona players maintained their lead until the final whistle, to regain the lead in La Liga from their traditional rivals Real Madrid.