Real Madrid and Barcelona will both be looking to strike a major blow in the Primera Division title race in the 80th 'Clasico' at the Bernabeu.
Although Madrid hold the clear upper hand in previous editions of this fixture, winning 50 of the 79 encounters in front of their own fans and losing just 15, there is precious little separating the two teams heading into tomorrow's match.
Both are locked on 77 points at the top of the standings and Madrid are only ahead due to a goal difference of plus one.
However, with Barca having won the first meeting 1-0 at the Nou Camp in November they only need a draw to take over at the summit on head-to-head record.
Knowing therefore that anything other than a win would see his side lose control of their own destiny, Madrid coach Manuel Pellegrini will settle for nothing less than three points tomorrow.
"We will go out for the victory. A draw is always a bad result for my team, we've never gone out looking for a draw. We've picked up a lot of victories away from home, and more at the Bernabeu, and this game is not going to be an exception," said Pellegrini.
"We have to show why we are leaders. We've always gone out to take the game to our opponents from the start and it will be no different on this occasion."
Madrid are the form team in La Liga with 12 successive victories behind them and 15 home wins out of 15 in La Liga this season.
They are also the top scorers in the division with 83 goals, 42 of which have been scored by forward duo Gonzalo Higuain and Cristiano Ronaldo - who between them have only made 45 La Liga appearances.
Barca are not short of firepower or form either, though.
Last season's sextuple winners have won their seven of their last eight league games and on Tuesday progressed through to the semi-finals of the Champions League after thumping Arsenal 4-1 in the second leg at the Nou Camp.
Barca will now face Inter Milan for a place in the final - which will be held at the Bernabeu.
On top of all that, Barca have a player who is widely recognised as the best in the world, and he is at the peak of his game.
Lionel Messi took his tally for the season to 39 with all four goals against Arsenal, and the Argentinian magician now has 15 goals in his last 10 games, including three hat-tricks.
Pellegrini added: "I'm expecting a very open match. Barca are going through a great moment, as is reflected in the points of both teams in the league. They are also in the Champions League so we have to have a great game, the same as them."
Barca won this corresponding fixture 6-2 last season to all but put that year's title race to bed, moving seven points clear of Madrid with just four games remaining.
That was one of the most painful defeats in Madrid's history, but Barca coach Pep Guardiola has ruled out something similar happening tomorrow.
"The 6-2 is unrepeatable. These things happen once in a lifetime, no more," he said.
Guardiola also played down suggestions this weekend's match would be the defining one of the season, although he conceded it is a key game.
"If there were only three or four games to go I would say it is an almost decisive match, but when there are seven left afterwards it's not so much, but it is very important," he said.
"It's not a final, but we need to play as if it was one. It's a game where the winner will strike a blow to the other."
Guardiola will be without Zlatan Ibrahimovic and Eric Abidal through injury for the match, but centre-back Gerard Pique has been passed fit to play.
For Madrid, Kaka is again missing, as are Pepe and Royston Drenthe, but Sergio Ramos and Xabi Alonso return after being suspended for last weekend's win over Racing Santander.
