Real Madrid have comfortably dispatched Mexican side Cruz Azul 4-0 in Tuesday's Club World Cup semi-final at the Stade de Marrakech, notching up their 21st straight win in the process.

The Spanish giants set the tone from the off when full-back Dani Carvajal crossed into the box, with Karim Benzema heading the ball towards Cristiano Ronaldo inside the six-yard box, but the Portuguese's effort was saved at close range by goalkeeper Jesus Corona.

It didn't take long for the Champions League holders to open the scoring, however, as Sergio Ramos made the most of an error by the opposition goalkeeper to nod the ball into an empty net on the quarter-hour mark.

Benzema then doubled Real's lead in the 36th minute after marauding into the box and turning in Carvajal's cross from the right flank.

Gerardo Torrado then wasted a good opportunity to reduce the deficit prior to the interval when he had a penalty saved by Iker Casillas.

Gareth Bale made it 3-0 five minutes after the restart, the world's most expensive player heading in Ronaldo's cross after the 29-year-old had been played in by Benzema.

With the result already beyond doubt, Isco went on to weave his way through the Cruz Azul defence to strike his side's fourth goal midway into the second half.

Real will face the winner of Wednesday's clash between Auckland City and San Lorenzo in the final on Saturday.