Lionel Messi's exquisite finish set Barcelona on their way to a potentially decisive 2-0 win at Real Madrid on Saturday to lift the champions three points clear of their arch-rivals at the top of La Liga.
After his brilliant four-goal Champions League haul against Arsenal on Tuesday, the Argentina forward struck in the 33rd minute at the Bernabeu before Pedro doubled the visitors' lead in the 56th with a clinical left-foot strike.
Both goals were created by Barca's Spain midfielder Xavi, the first when he chipped the ball to Messi over the Real defence and the second when he sent Pedro clear to finish with a low strike beyond Iker Casillas.
La Liga top scorer Messi twice came close to adding to his 27 goals of the campaign and Barca goalkeeper Victor Valdes was rarely troubled as Real struggled against the European champions' slick passing game.
The victory puts Barca on 80 points with seven matches left and leaves the big-spending Madrid club, who have 77, facing a season without silverware after their exits from the Champions League and King's Cup.
It was a fourth straight win in the "Clasico" for Barca coach Pep Guardiola and he becomes the first manager of the Catalan club to claim two straight away wins over Real.
After a tense opening to a contest Marca sports daily had dubbed "the match of the millennium", Messi squared the ball to Xavi and he lifted a delicate chip over the static defence.
Messi timed his run to perfection, controlled the ball on his chest and dinked a shot past Casillas into the net.
Striker Gonzalo Higuain fluffed a chance to put the hosts level in the 41st when a mistake by Gerard Pique put him clear but he did little to boost his chances of starting for Argentina at the World Cup by slicing his shot into the crowd.
Xavi underlined why he will be crucial to Spain's bid for a first World Cup triumph in South Africa when he carved open the Real defence with a superb through ball and Pedro raced into the area to double Barca's lead.
Although the Catalans did not match their 6-2 thrashing of Real in last season's Clasico in the Spanish capital, their performance was no less dominant.
Real coach Manuel Pellegrini threw on veterans Raul and Guti to try to spark the team into life but they faded badly as the final whistle drew near and the disgusted home fans began to head for the exits well before the finish.
Real president Florentino Perez spent close to a quarter of a billion euros ($334 million) on players including Cristiano Ronaldo and Kaka last summer but any hopes of instant titles appear to have been dashed.
Financial experts say his strategy of buying high-profile players to boost sales of merchandise needs success on the pitch, especially in Europe, to support it but they may now have to wait until next season to reap the fruits of their massive investment.