Barcelona dealt a stinging blow to Real Madrid's title hopes when Luis Suarez and Neymar continued their scintillating form to fire the champions to a stunning 4-0 victory in the La Liga 'Clasico' this evening.

Suarez struck twice either side of goals from Neymar and captain Andres Iniesta as Barca humiliated their arch rivals with an imperious performance at the Bernabeu to surge six points clear at the top after 12 matches and ratchet up the pressure on under-fire Real coach Rafa Benitez.

Barca's dominance, which prompted the angry Real fans to roundly whistle their own team and chant for president Florentino Perez to step down, was all the more remarkable considering coach Luis Enrique had started with a fit-again Lionel Messi on the bench.

The Argentina captain, who has been out for nearly two months with a knee injury, came on for Ivan Rakitic just before the hour and promptly sent Suarez clear to score the European champions' fourth.

An utterly dominant Barca could easily have added to their tally in the closing stages and Real's humiliation was complete when substitute Isco was shown a straight red card for a wild lunge at Neymar six minutes from time.

"We played what was quite honestly a complete match in every sense," Iniesta, who was given an ovation by the home fans when he was substituted late on, told Spanish television.

"There is a long way to go, it's not decisive at all but we are going away very, very satisfied," the Barca captain added.

Chasing a sixth La Liga title in eight years, Barca have 30 points, with Real, who lost 3-2 at Sevilla in their previous outing, on 24.

Atletico Madrid can climb back to within four points of Barca and leapfrog Real into second with a win at promoted Real Betis on Sunday.