Barcelona stand on the brink of La Liga history, targeting a 10th consecutive victory to start the league season.
It will surpass the mark set in 1968-69 by Real Madrid, who will have the chance to end that remarkable run on Sunday when the sides meet at Camp Nou.
Barcelona head into El Clasico on the back of a 4-2 Champions League defeat by Paris St-Germain, giving Jose Mourinho's men the perfect opportunity to capitalise on that setback and wreck the record bid of their rivals.
'Madrid with Mourinho wins trophies'
Real boss Mourinho has insisted his team's most recent performances, two 4-1 victories against Sevilla and RB Leipzig, would count for little in a fixture that has such global appeal and standing.
"We are in a good dynamic, we play well, we score goals, but the Clasico is different. What we have done before has no influence," he said.
"There are other important matches in the world, but this is the only Clasico, the world stops."
Some of football's biggest names with be involved, with six of this year's 30 Ballon d'Or nominees available - Barcelona's Pau Cubarsi, Rodri and Lamine Yamal, and Real Madrid trio Marc Cucurella, Jude Bellingham and Kylian Mbappe.
There will be huge individual battles between them on the pitch too.
Cucurella could find himself trying to stop national team-mate Lamine Yamal down Barcelona's right, while centre-back Cubarsi could once again face Mbappe, renewing their rivalry after Spain's 2-0 victory over France in the World Cup semi-final.
Striker Mbappe, though, has been in prolific form for Real, scoring 12 goals in 12 appearances this season.
In midfield, Rodri and Bellingham could provide another fascinating clash between two of the game's leading players.
With a six-point gap to leaders Barcelona, Mourinho acknowledged his third-placed side were still adapting to his methods and argued comparisons with more established teams were premature.
"We've been together for three months if you take away pre-season and international breaks," he said.
"The players are still getting to know me and the way I do things."
He also dismissed the idea of making sweeping tactical changes specifically to contain Lamine Yamal.
"He's a great player, we respect great players. We aren't going to completely change things. We won't forget the way we do things," said Mourinho.
"Madrid with Mourinho wins trophies."
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'We have to be careful and prepared' - Flick
Barcelona manager Hansi Flick believed his side were ready for the challenge of Real, but admitted they must address defensive weaknesses exposed by PSG in midweek.
"The players have recovered and they're ready for this game," he said at his pre-match media conference.
"El Clasico is different, the best match our sport has to offer. Everyone will be watching. You can only win three points, but it's so much more than that."
The German praised Madrid's attacking quality and warned Barcelona could not afford to be complacent.
"I expect a very confident team," he added. "Real Madrid is a great club with great players and a great coach. They have players with great quality in the final third. They've shown that in recent matches. We have to be careful and prepared."
Flick stressed the importance of positioning and organisation as they prepare to contain Mbappe, although Vinicius Jr will be missing for the visitors through suspension.
"Our positioning is key, both with and without the ball," he said.
"Without the ball, we need to maintain the right distances between players and stay compact, which is especially important when playing with such a high defensive line."
Barcelona's attack, though, has been prolific this season, scoring 50 goals in their 12 games, but questions remain over their defensive solidity, with the Spanish champions having conceded 15.
How can Real beat Barcelona?
Madrid's best chance of success could lie in disrupting Barcelona's possession and exploiting the spaces behind when their opponents commit players forward.
A compact defensive shape, disciplined pressing and quick transitions could force Barcelona away from their preferred rhythm. Rather than chasing possession, Madrid must remain organised and choose the right moments to attack.
Lamine Yamal will be central to Barcelona's attacking plans, while Madrid will look to use their pace and quality in the final third to test the home defence.
The midfield battle will also be crucial. If Madrid can win second balls and prevent Barcelona from finding space between the lines, they can reduce the pressure on their defence.
However, defensive discipline alone may not be enough. Madrid must take their chances when they arrive, particularly if Barcelona dominate possession.
Set-pieces could provide another route to goal and Flick specifically identified them as a threat.
"We know Real Madrid's strengths, and they're among the best at set-pieces," he said. "We have to defend better than we did in Paris."
For Barcelona, victory would not only set a record, but strengthen their position as clear early-season title favourites, opening up a nine-point lead over Real Madrid.
For Mourinho's men, halting that run would reduce the deficit to three points and deliver a major psychological boost to revive their hopes of domestic success this season.
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