The result was not enough for them to end 2011 on top of La Liga - Madrid are three points clear - but the defending champions proved that they remain the team to beat. In late November 2010 the Madrid camp was in shock after their 5-0 hammering at the Camp Nou.
But while Madrid and Mourinho have made real progress since then, in seven Clasicos this year - two in La Liga, two in the Champions League, two in the Spanish Supercup, and the Copa del Rey final - Barcelona have won three, while Madrid have won just one. That one victory came in extra-time in the Copa del Rey final in April, when a brilliant Cristiano Ronaldo header handed Real the Cup for the first time in 18 years. However, Mourinho insisted recently that if he could only win one Clasico in 2011, it would always have been the Copa final, because there was a trophy on offer.
"You cannot call our year a failure when we are on top of the table, having reached the semi-finals of the Champions League and won the Cup last season," said a defiant Mourinho. "If we were up against a slightly less good opponent then our job would be easier," he added in a nod towards Catalonia. "If we played in another league then we would win it easily."
Questions could be asked about Barcelona's hunger after another exceptional year in which five trophies were won, including a third straight league title and another Champions League. However, Guardiola's side have proven time and again that finding motivation is not a problem, and the mere presence of Mourinho in the enemy dugout keeps them going.
Guardiola deserves enormous credit for refusing to rest on his laurels and overseeing the tactical evolution of his team in an attempt to stay one step ahead. "When it comes to tactics you have to think about what the opposition does and the players who can hurt you. What I've done this season is a response to the game plans our rivals are now adopting against us," he said.
"As time goes by, people get to know you better. They pose problems for you and you have to come up with solutions." Guardiola is also helped by being able to call on Lionel Messi, and the Argentine's individual battle with Ronaldo has been fascinating. The two best players in the world continue to score goals at an astonishing rate - both netted 53 goals in all competitions in 2010-11, and both average more than a goal a game this season.
While Messi has 17 in the league so far, Ronaldo has 20. But the gap between Barcelona and Real Madrid and the rest continues to widen. The big two can rely on television revenue that far outstrips that of the rest of the division, and the other clubs have made moves to push for a new collective TV deal.
Even if they invariably are, the rest should not be forgotten. As Villarreal president Fernando Roig said: "I'd like to see Madrid and Barcelona have a league that consists only of the clasicos - that would be pretty boring." He is right, but the global economic financial crisis has hit hard - Valencia have lost David Villa, David Silva and Juan Mata in the last 18 months, but remain the third-best team in the country.
Sevilla, Atletico Madrid, and Villarreal can no longer compete, while a large proportion of La Liga clubs have no shirt sponsor. Levante have enjoyed remarkable success, though, first in staying up last season, and then in challenging consistently at the top of the table in the first half of this campaign - the Valencian outfit have been a permanent fixture in the top four since late September.
Malaga are the one major exception. Almost 60 million euros was thrown at signings in the summer by their Qatari owner Sheikh Abdullah al-Thani, and while inconsistency remains a problem, they are on course to break into the top six, which was their minimum aim for the season. But they remain some way off challenging the big two.