Karim Benzema took advantage of Victor Valdes's error after 20 seconds, to get Real Madrid on the board, as the home squad looked particulary effective in the early going.
But at the half-hour mark it all turned, as Barcelona evened the match as Lionel Messi fed Alexis Sanchez with an excellent through ball, and the young forward did all the rest.
Eight minutes after halftime, Xavi Hernandez's shot deflected off Marcelo and into the goal. Iker Casillas couldn't get his fingers on the ball, as it hit the post and went in.
Barcelona would add a third goal in the 66th minute thanks to an excellent cross by Dani Alves that found Cesc Fabregas who headed the ball in.
There was plenty of scoring, as the rivals played hard for 90 minutes. There was also plenty of yellow cards but no red cards.
Real Madrid took 17 shots with five on goal, while Barcelona took 12 shots, with seven on goal. Barcelona controlled possession for 63 percent of the match.
Here are the highlights from the match: