FEW "old firm" rivalries match that between Real Madrid and Barcelona, and last Saturday's clash not only provided yet another mega spectacle at the Nou Camp, but Barcelona's 3-0 home win may have marked an important turning point in this season's Spanish championship.
Barcelona fans had reason to be doubly joyful, since they not only wiped the eye of the "auld enemy", reigning champions Real, but that win also came on a day when league leaders Atletico Madrid were surprisingly beaten 1-0 at home to Sevilla.
In mathematical terms, Saturday night's win puts Barcelona in second place, eight points adrift of Atletico. In soccer "real politik" terms, Saturday's results mean that Atletico now know they have a real fight on their hands.
There are still 18 league left, a long and winding road for the current league leaders who will be looking anxiously over their shoulders at a Barcelona side which may take heart and momentum from the weekend's results.
Ironically, despite the white hot atmosphere created by more than 115,000 mainly Catalan fans at the Nou Camp, it was the visitors, Real Madrid, who made the more impressive start.
Indeed, had Real's Chilean Ivan Zamorano, their Dane Michael Laudrup and defender Enrique Quique made better use of brilliant through balls from the promising Raul Gonzales, Real could well have been two or three nil up after the first half hour.
Real, of course, sacked their Argentine coach Jorge Valdano just three weeks ago, following a disappointing series of results.
New coach Arsenio Iglesias, formerly with Deportivo La Coruna, had got off to a bright start heating Athletic Bilbao (5-0, away), Oviedo (2-1, away) and Betis (4-2, home) in his first games in charge.
Two factors undoubtedly helped Iglesias get Real back on their feet. Firstly, he did not face the dressing room hostility of senior Real players, in particular Laudrup a hostility that had contributed to Valdano's sacking. Secondly, on the tactical front, Iglesins has opted for a more cautious line up in which everyone, with the exception of Zamorano and Laudrup, is expected to cover back and defend.
Real's new self belief and their different tactical line up were all too evident in an opening half hour when Barcelona huffed and puffed but created little. Real sat back, looked steady and consistently broke on dangerous counter attacks.
However, Real's failure to put away their chances cost them dear and it was Barcelona who struck first blood with their first real chance of the game. Right back Albert Ferrer went past a defender to get to the line following a throw in before sending in a low, hard cross which Barcelona's Bosnian striker Meho Kodro cleverly drove between the legs of Real goalkeeper Francisco Buyo for a 36th minute goal.
Just before half time, Barcelona ought to have gone 2-0 up when the impressive 19 year old, Ivan De La Pena, was sent through, only to have his shot well saved by Buyo.
The second half began as the first ended, with Barcelona coming close to scoring. Kodro was sent clear through on the right, but failed to get his close range shot on target. Within five minutes, Barcelona were themselves let off the hook when Real's Luis Enrique hesitated too long in front of goal after having been brilliantly set up by Laudrup.
When Real were denied an apparently clear penalty seven minutes later, after Quique had been brought down by De La Penn, it became clear that this was not going to be their night. The further the game went, the more convincing Barcelona became, and their second goal, from Portuguese winger Lois Figo in the 71st minute, was thoroughly deserved.
At that point, the contest was over and the third Barcelona goal, scored in injury time by Kodro, owed more to Real's discouragement than to Barcelona's superiority.
One interested observer of the proceedings was the Juventus coach, Marcello Lippi. Juventus are due to meet Real in perhaps the most tasty of all the Champions' Cup quarter finals next month, and therefore Lippi's opinion is not merely academic
"I thought Real looked like a good side in the first part of the match. In the end, Barcelona ran out clear winners, but the final result did not reflect the way the game had gone," Lippi said on Sunday.
While Barcelona made the most of their luck, rivals Atletico Madrid appeared unlucky in their 1-0 home defeat by Sevilla.
Given that the Spanish table has an unfamiliar look about it, with Compostela in third one point behind Barcelona, and with Valencia and Espanol a further point back in joint fourth, it could be that the Spanish contest has already become a dual between Barcelona and Atletico Madrid. Compostela, Valencia and Espanol won't last the pace.
Barcelona's greater experience and stronger squad could yet swing the title their way. One thing is sure. Atletico Madrid midfielder Delfi Geli came up with the understatement of the weekend when saying
We're going to have to work hard and struggle a bit this week."
And maybe not just this week.