There is a lot riding on every El Clasico, but this Saturday's match between Real Madrid and Barcelona (20:00 BST) feels particularly momentous with Real on the verge of history.
Carlo Ancelotti's side are a win or draw away from equalling La Liga's longest unbeaten run.
The Spanish champions last lost 13 months and 42 games ago.
It's quite apt then that their next match is against fierce rivals Barcelona, who currently own the outright record of 43 games unbeaten set between 2017 and 2018.
Real Madrid were convincingly beaten 3-1 by cross-city rivals Atletico Madrid on September 24, 2023.
Since then they have recorded 31 wins, 11 draw and zero defeats.
Their run propelled them to last season's La Liga title, which they won by 10 points, and they also stayed unbeaten throughout the Champions League, which they lifted by beating Borussia Dortmund in the final.
In terms of personnel, often overlooked Uruguay defensive midfielder Federico Valverde has been an instrumental figure in Real's run, playing in all but one of their matches.
Meanwhile, nobody has scored more league goals for Los Blancos since that Atletico loss than Vinicius Junior with 19.
England midfielder Jude Bellingham is the next best with 14 strikes.
Barcelona need to beat Real Madrid on Saturday to keep their outright crown.
The La Liga leaders' record run started with a 3-2 win against Real Sociedad in April 2017 and ended when they lost 5-4 to Levante in May 2018, two games shy of going unbeaten for a full season.
When you compare the two runs, offensively Barcelona's side of six years ago has the edge.
Barca forward Lionel Messi was in sublime form during the 43-game streak, managing 58 goal involvements. For comparison, Vinicius and Bellingham have so far combined for 48.
Barcelona also recorded more wins (34 to Real's 31) and took more points (111 to 104); although Real have played that one game fewer.
In defence, Real Madrid boast more clean sheets, with 23 compared to Barcelona's 19, and fewer goals conceded (27 for Real and 33 for Barca).
Plus, Real have continuity on their side with Ancelotti having overseen all of their run, whereas Ernesto Valverde replaced Luis Enrique as Barcelona manager at the end of the 2016-17 season.
So, will Real Madrid get to the magic number 43?
Form is on their side. They have faced Barcelona three times since the start of their streak and have won on all three occasions (twice in the league and once in the Spanish Supercopa final).
Should they leave the Santiago Bernabeu unscathed on Saturday they can then start to target Europe's big five leagues record of 53 set by Bayern Munich in March 2014.