كتب : Hatem Maher
The Spanish international dished out two assists as Barca moved three points clear of Real at the top with goals from World Player of the Year Lionel Messi and 22-year-old winger Pedro either side of the interval.
They ensured they would have the better head-to-head record if they finished level on points with Real, having beaten them 1-0 at Nou Camp in November.
With seven matches remaining before the end of the season, Barca look favorites to win a second consecutive league title.
Barcelona had an early penalty claim waved away by the referee after Messi was apparently brought down by Alvaro Arbeloa inside the area.
The first-half cautiousness of both sides restricted their attempts to some tame efforts.
Cristiano Ronaldo's darting runs were repeatedly thwarted by Barcelona's centre back Gerard Pique, who delivered a solid display to annoy the hosts.
The special skills of Barcelona men eventually favored them as they broke the deadlock after 33 minutes.
Messi found Xavi on the edge of the area and jinked into the area to control the midfielder's superb scooped pass, hold off Raul Albiol and place the ball past keeper Iker Casillas.
Xavi once again mesmerized Real's defense to gift Barcelona a second goal in the 56th minute.
Pedro timed his run to perfection to latch onto a deft through pass from Xavi, break clear of Arbeloa and send a left-footed shot into the far bottom corner.
Portuguese wizard Ronaldo should have narrowed the gap on two occasions but was denied by Barcelona keeper Victor Valdes.
Rafael van der Vaart wasted a glorious opportunity when he broke the offside trap to go clear but he could not beat the in-form Valdes.