Arguably the biggest match in domestic football will attract a reported half a billion viewers worldwide.
The clash between Real and Catalan giants Barca always promises to be an intriguing contest, regardless of the context.
But with just one point separating La Liga leaders Barca from second-placed Real, the mouth-watering fixture has plenty of extra spice.
For large parts of the campaign it was big-spending Real who led the way, a club-record 22-match winning streak before the turn of the year helping Carlo Ancelotti's men to the summit.
However, a dip in performance levels in 2015 has led to heavy criticism from the Santiago Bernabeu stands and the Spanish press.
Forward Gareth Bale bore the brunt before his double in last weekend's 2-0 victory over Levante silenced the boo-boys to an extent.
But the costly draw and defeat to Villarreal and Athletic Bilbao in the matches preceding that fixture allowed in-form Barcelona to move top.
Luis Enrique's men, who beat Manchester City 1-0 to make the UEFA Champions League last eight on Wednesday, have dazzled by winning nine of their past 10 Liga matches, superstar Lionel Messi galvanising his team-mates with 17 league goals in 2015.
With the gap so minimal, though, the pressure is high for both teams and Barca's Luis Suarez is expecting the match to have the feeling of a final.
"It's a final. Real Madrid are always Real Madrid," he told Gol TV.
"That sort of game means a lot for morale. In terms of motivation, it gives you a lot of confidence and we hope that it will be a good show for spectators."
Sunday also sees rock-bottom Cordoba start the post-Miroslav Djukic era at David Moyes' Real Sociedad.
Djukic won just three matches since taking the reins last October and the team have been in free fall with eight straight defeats.
Strugglers Deportivo La Coruna host Espanyol, while Sevilla hope to boost their UEFA Champions League prospects at Villarreal.
Champions Atletico Madrid have seen the defence of their title stall with three straight league draws and Diego Simeone's side, who needed penalties to beat Bayer Leverkusen and make the Champions League quarter-finals on Tuesday, will look to return to winning ways at home to Getafe on Saturday.
Relegation-threatened Levante and Granada have home fixtures against Celta Vigo and Eibar, while Malaga and Almeria visit Rayo Vallecano and Athletic Bilbao.
The weekend kicks off with in-form Valencia travelling to Elche on Friday.
