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Real Madrid beat Athletic Bilbao on Wednesday to go seven points clear at the top of La Liga.
Real Sociedad will attempt to halt Real Madrid's march away from La Liga's chasing pack on Saturday in a battle of first against third at the Reale Arena.
Madrid have stormed seven points clear at the top of the table after seven consecutive victories in all competitions, with nine wins and a draw recorded in their last 10.
Two wins in four days against tough opponents in Sevilla and Athletic Bilbao have seen Madrid emerge as clear favourites in the title race and it remains to be seen now which of those sides beneath them, if any, can keep up.
Real Sociedad were top themselves only a few weeks ago but a draw with Valencia and defeat by Espanyol has checked the momentum of Imanol Alguacil's side, who will be desperate to avoid a third consecutive disappointment on Saturday.
They might take encouragement from Madrid's performances, which have not been as convincing as the results.
Both Sevilla and Athletic squandered numerous chances at the Santiago Bernabeu and Real Sociedad will believe their attacking talents like Alexander Isak, Mikel Oyarzabal and David Silva can cause problems.
"Seven wins out of seven is not luck," Madrid coach Carlo Ancelotti insisted.
"This team has character. When we don't win with our quality we have other strengths we can use."
There are also question marks over Madrid's freshness for this fixture after a demanding couple of weeks during which Ancelotti has continued to stay loyal to a consistent core of players.
Only one or two positions have been rotated and that could leave some of Madrid's more seasoned veterans – like Karim Benzema, Luka Modric, Toni Kroos and Casemiro – lacking physical sharpness.
"We have had three matches very close together and we don't have time to rest," said Ancelotti on Wednesday.
"I will have to think carefully about my decisions this weekend."
Madrid might also have one eye on next week's final Champions League group game at home to Inter Milan.
Both teams have admittedly already qualified for the last 16 but first place is still to be decided and that could prove crucial given the quality of some of the other sides going through in the competition.
Barcelona, Atletico Madrid, Sevilla and Villarreal all face nail-biting European games next week as they scramble just to make the knock-out stages.
Barca's assignment away at Bayern Munich is particularly tough but they cannot afford to take fifth-placed Real Betis lightly on Saturday, with five points still separating Xavi Hernandez's team and La Liga's top four.
Sevilla, meanwhile, in fourth go up against Villarreal in 12th, with Sevilla looking for a morale-boosting victory before they play away at Salzburg on Wednesday.
Atletico Madrid, the reigning champions, could yet be Real Madrid's closest challengers in the league after a 4-1 thrashing of Cadiz last weekend offered signs they could be turning a corner.
Atletico host struggling Mallorca on Saturday before a crunch trip to Porto on Tuesday, with a demanding week ending with the Madrid derby at the Santiago Bernabeu next weekend.
Fixtures (GMT)
Friday
Granada v Alaves (2000)
Saturday
Sevilla v Villarreal (1300), Barcelona v Real Betis (1515), Atletico Madrid v Mallorca (1730), Real Sociedad v Real Madrid (2000)
Sunday
Rayo Vallecano v Espanyol (1300), Elche v Cadiz (1515), Levante v Osasuna (1730), Celta Vigo v Valencia (2000)
Monday
Getafe v Athletic Bilbao (2000)
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