Real Madrid suffered a shock defeat against Rayo Vallecano at the Estadio De Vallecas, MySportDab reports.
Barcelona had already gone two points up after a convincing 2-0 win over Almeria.
A game which saw legendary La Liga and Spain defender Gerard Pique wave goodbye to teeming supporters after announcing his imminent retirement earlier.
Gerard Pique was treated to a heroic exit, but what was important was the Catalans returning to the top of La Liga over arch-rivals Real Madrid.
Real Madrid needed to win their tie against Rayo Vallecano to return to the top spot.
It was disappointing for the Carlo Ancelotti-led team as they stumbled against a resilient and spectacular Rayo Vallecano side.
Apart from the surprise defeat to Los Blancos in a five-goal thriller, the stats from the match showed something exciting.
Real Madrid scored only two goals in the game. Modric converted a spot kick in the 37th minute, and Brazilian star Militao scored in the 41st minute.
But they had only two attempts on target, while their opponents, who equally scored two goals in the first half, had seven shots on target.
Real Madrid dominated possession, having 55% of the ball, but had fewer attempts on goal than Rayo Vallecano.
The host scored their winner from the penalty spot in the 67th minute. With 23 minutes left in the game, Real Madrid could not find an equaliser.
They finally settled for their first defeat of the season and are now two points behind Barcelona, who can extend it to five points more after going head-to-head with Osasuna.