But so fair and foul a day Mourinho could scarcely have envisaged. Eschewing the game plan preannounced by his right-hand man, Aitor Karanka, in Friday's news conference and opting to field the same formation that had been so clinically dissected in a 5-0 defeat in Camp Nou last season, Mourinho sought again to go toe-to-toe with the purveyors of a balletic soccer style. Leo Messi failed to score, and Cristiano Ronaldo erred in the most basic decision-making to the detriment of his side, but the Clasico has long been about more than the two most lauded players on the planet. The match has become a duel of styles, of ethos. "We don't know how to play any other way," Xavi said after the match. The only slight tweak on Barcelona's side was Pep Guardiola's shift to a back three. "I wanted to do it after two or three minutes, but after conceding so early, I wanted to stabilize the team. We held on for half an hour and then moved to three at the back because we needed to find spaces."

Guardiola's decision to field Alexis Sanchez in place of David Villa robbed Real of one of its most potent attacking forces, Marcelo, and the Chilean also provided the response to Real's opener via a defense-splitting pass from Messi. Despite going behind a goal in 22 seconds -- the fastest goal in the history of the Clasico -- Barca never betrayed its ethos of patient probing while Madrid, sensing a famous victory, tripped up on its own haste. Twice Ronaldo had the goal at his mercy, and twice he failed to execute. Against other opposition, there is little doubt that he would have scored, but Real appears to have a clemency switch that can be activated only by the visit of its archrival. Fifteen straight victories in all competitions is a mark few teams can boast, and Real cannot be accused of a lack of industry -- 17 attempts from less than 40 percent possession displays a willingness to get forward, if nothing else tangible.

Guardiola has now overseen 12 Clasicos at the helm of Barcelona and has been defeated just once, in last season's King's Cup final. Against Mourinho's Real his record is won four, tied three, lost one with a 17-8 aggregate score line. The weight of such figures on the opposition should not be underestimated.

Yet Barcelona's greatest hold over its eternal enemy is the indecision it fosters among it. The 4-3-3 that served to overcome Valencia earlier in the season could have stymied Barca on this occasion, but despite a public announcement of this shape on Friday from Mourinho's lieutenant, Karanka, the Portuguese again opted to play the opposition, as Xavi had predicted during the week, "one-on-one." It could have worked, had Real had the patience to maintain possession of the ball as it has on so many occasions this season. But an endemic desire to put Barca to the sword when its front foot was forward so often led to bad decision-making in the final third with a snap shot favored to a pull-back when a colleague was better placed for a goal attempt. Ronaldo was the chief perpetrator of such impetuousness, but when even Lass Diarra opts for a 30-yard belter instead of a ball to a teammate in space, it is clear that a lack of sangfroid induces Real's players into rash decisions.

In the aftermath, Mourinho cursed his side's luck, and not without good reason. There is a case for reviewing Messi's continued presence on the field after a rash challenge that could have brought about a second yellow. That instance and Barca's second goal, a heavily deflected Xavi effort that sneaked past Iker Casillas' far post, were undoubtedly game-altering moments. But when all is said and done, Real again failed to capitalize on a momentum born of 10 consecutive league victories and home advantage to open up a six point gap and possibly a nine-point chasm in December. The exodus of the home support before the final whistle sounded told its own tale.

Call it luck, or a lack of mental fortitude, as suggested by Mourinho, but Barca has hauled Real back in the standings. However, as the Portuguese manager was at pains to point out after the match, anything other than a loss at Sevilla next weekend will leave Real leader before the winter break -- something that has not yet occurred under Mourinho and a small psychological boon to soothe the familiar sting of a Clasico defeat for the capital club.