Just over a month ago Real Madrid held a 10-point lead over Barcelona atop La Liga and it appeared purely a matter of before Jose Mourinho would be popping open the champagne corks to celebrate his first Spanish league title.
But fast forward to today and that once commanding lead looks mighty precarious standing at just four points heading into the latest El Clasico on Saturday.
While Real have stuttered somewhat in the quest for its first title since 2008, recording three draws in their past seven league outings, Barcelona have kicked down on the accelerator to win 11 consecutive league games.
Clearly with the edge in form, Barcelona also has the psychological upper-hand in terms of recent meetings between the two great sides.
The Catalan giants have won six of their last seven league matches against Real, drawing the other, while Los Blancos have only won once in 10 meetings with their bitterest of rivals since Jose Mourinho took the reins at the Bernabeu in 2010.
Yet, while for Barcelona only a win will do, Real know that if they can emerge from the Camp Nou on Saturday with a share of the points they will have all but secured themselves the La Liga crown.
With just four matches to play after El Clasico, it would take a collapse of devastating proportions to let a four-point lead slip.
Further encouragement will be garnered by Real by the fact that Barcelona has had 24 hours less to recover from the sides' respective Champions League semi-final first-legs and Barca will also have a day less to prepare for their second-leg next week.
Both clubs endured somewhat surprising and disappointing results in midweek, but it is Barcelona, having lost without the cushion of an away goal, that will likely find it more difficult to get back to a positive mindset and focus on the all-important El Clasico.
But Barcelona does have options to refresh their side both physically and mentally for El Clasico. Cesc Fabregas, arguably most culpable on a night of missed chances against Chelsea, could well drop out of the side, with one or both of Pedro or Issac Cuenca likely to come in.
Barcelona was sorely lacking in width against Chelsea and Real could well block off the center of the pitch in a similar fashion to the Blues. That will make the enhanced ability to play out wide that Cuenca, Cristian Tello and Pedro bring to the side potentially decisive.
Mourinho will also likely make changes to his Real Madrid side from the one that went down to Bayern Munich on Tuesday. Los Meringues were perhaps somewhat caught out by Bayern playing an extra man in the center of midfield and Mourinho is unlikely to allow the team to be similarly undermanned on Saturday.
For that reason Mesut Ozil may have to settle for a place on the bench with Esteban Granero coming in to shore up a three-man midfield along with Xabi Alonso and Sami Khedira.
For the first time in Mourinho's reign at the Bernabeu, Real go into an El Clasico knowing that a draw would be a fantastic result; something that, despite Real's incredible goal scoring record this season, could bring out Mourinho's defensive instincts.
But Barcelona have all the momentum going in their favor in La Liga and perhaps more importantly they continue to maintain a psychological edge over their great rivals Real in one-on-one contests.
Prediction: Barcelona 3-1 Real Madrid