Xavi Hernandez's Barcelona was a reborn side when it inflicted a humiliating 4-0 defeat on archrival Real Madrid at the Santiago Bernabeu on Sunday.

Pierre-Emerick Aubameyang, who arrived on a free transfer from Arsenal in January, scored twice in the Catalans thrashing of Carlo Ancelotti’s LaLiga leader on its own ground.

A sold-out crowd watched silently as a much-improved Barca under the command of new coach Xavi dominated "El Clasico" from the get-go.

With Ousmane Dembele and Ferran Torres exposing Real's defensive frailty on the flanks, Barca opened the scoring in the 29th minute with an Aubameyang header from a Dembele cross.

Barca kept up the tempo against a disorganized and lifeless Real Madrid and extended its lead when defender Ronald Araujo headed in from a Dembele corner.

Ancelotti tried to change the dynamic, making two substitutions during the break but Barca scored in the first minute of the second half with an angled shot from Torres after a backheel by Aubameyang.

Five minutes later, former Manchester City forward Torres returned the favor, teeing up Aubameyang for his second goal.

Barca had several opportunities to extend its lead, but Real goalkeeper Thibaut Courtois avoided any further humiliation.

With Real Madrid sitting comfortably on top of the standings with 66 points, Sunday’s Clasico was never likely to determine the fate of La Liga title race.

But pride was on the line and Xavi's much improved Barca showed that its recent return to form was no fluke.

After its fifth consecutive league win, Barca is third in the standings on 54 points with a game in hand, three points behind second-placed Sevilla.

Having fallen as low as ninth in the table when Ronald Koeman was sacked in October, Barca has been revitalized under Xavi.

It is unbeaten since an extra time defeat by Athletic Bilbao in the Copa del Rey on Jan. 20 and has scored 24 goals in its last seven league games.

"We didn't expect this result, but our objective was achieved. We came to win and show what we are worth," Barca's Sergio Busquets told reporters.

"If we still have a small chance to make a run for the title, we will fight until the end. It's very difficult but in football anything can happen. We are Barca."