Barcelona thrashed eternal rivals Real Madrid 4-0 in their own backyard to open up a six-point lead at the top of the Primera Division.
The Catalans began the game with star man Lionel Messi on the bench but took a commanding lead at half-time thanks to goals from Luis Suarez and Neymar.
Andres Iniesta added a superb third early in the second period, and Suarez completed the rout thanks to a pass from substitute Messi.
Barcelona, meanwhile, sit pretty at the top of the table after this most spectacular of performances, which must rank as their best display against their bitter rivals since Pep Guardiola's side beat a Madrid side coached by Jose Mourinho 5-0 in 2010.
Although Messi was named in the squad having recovered from a knee injury he sustained eight weeks ago, Luis Enrique left the Argentinian on the bench at the start, while the in-form Sergi Roberto joined Neymar and Suarez in attack.
Benitez has been questioned in the Spanish press for his cautious approach since taking charge of Madrid and opted for a more attacking line-up than usual, dropping holding midfielder Casemiro and handing a first start to James Rodriguez since August, while Karim Benzema made his comeback from a hamstring injury sustained over a month ago.
Even without their talisman in the side, the visitors looked comfortable from the off, playing with freedom and confidence.
Suarez saw an early shot loop over the bar but it was not long before the visitors were in front.
Sergi Roberto made a powerful towards the heart of the Madrid defence before playing in Suarez, who clinically curled his shot past Keylor Navas with the outside of his right boot.
Barca, despite losing centre-back Javier Mascherano to injury, were very much on top and worthy of their lead, while Madrid looked rattled.
Neymar tried to double the lead from a free-kick but could not beat Navas, while at the other end Claudio Bravo was equal to Madrid's first attempt at goal, a strike from Rodriguez.
The Chile international nearly embarrassed himself towards the end of the first half as he failed to claim a Madrid corner, but he and Barca got away unscathed - and just a moment later the Catalans got their second goal.
Suarez won the ball back from Modric around the centre circle and found Iniesta, who dribbled forward unchallenged to lay the ball on for Neymar, whose shot bounced off Navas and into the net.
Madrid's defence was being ripped to shreds and they could even have conceded a third before the break but were saved by Marcelo heading Suarez's mis-hit shot off the line before Varane got in the way of Ivan Rakitic's rebounded effort.
Neither coach made any changes at the break and Madrid improved slightly, with Marcelo missing a gilt-edged chance and Rodriguez forcing a low save from Bravo shortly after the re-start.
However, Barcelona were merely waiting for their next moment to strike. Iniesta surged forward and played a one-two with Neymar on the edge of the area, rocketing the ball into the top corner following the Brazilian's stylish back-heel pass.
Barca had brought Madrid to their knees while Messi was still on the bench but the all-time top scorer in this fixture was not about to miss out on the fun.
Shortly after replacing Rakitic the Argentina forward picked the ball up from deep and picked out a wonderful pass towards Alba, who helped it into the path of an unmarked Suarez to calmly slot into the far corner and make it 4-0.
Madrid's humiliation was compounded by the red card to Isco, who lashed out at Neymar less than half an hour after entering the game, but they were in fact fortunate not to concede a fifth, with Munir El Haddadi squandering two glorious opportunities to round off an already stunning Barcelona victory.