Cristiano Ronaldo registered a five-goal haul for the first time in his distinguished career as Madrid bounced back from losing a potentially-decisive clash against Barcelona before the international break.
Moreover, coach Carlo Ancelotti has almost a fully fit squad to choose from for the first time in five months with centre-back Pepe the only doubt for the trip across Madrid.
Playmaker Isco is available once more after missing out through suspension against Granada, but Ancelotti insisted he is reluctant to make too many changes after such a stunning return to form.
"We are in great form. We have never been in this physical shape before, especially at this time last season."
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Rayo come into the game in fine form themselves on the back of three victories to take them into the top half of the table.
Manucho was the match winner for Paco Jemez's men in a 2-1 win at Eibar on Friday and the former Manchester United striker is confident of springing a surprise against their city rivals.
Rayo's main threat will be a well-known one to Madrid fans as former Real youth product Alberto Bueno's 16 La Liga goals have made him the highest scoring Spaniard in the division.
Barca maintained their stranglehold on the title race in less dramatic fashion with a hard-fought 1-0 win over Celta Vigo on Sunday to remain four points clear at the top of the table.
However, the Catalans will be confident of a more comfortable evening at home to managerless Almeria on Wednesday.