Karim Benzema bagged a late first-half goal, while Cristiano Ronaldo sealed the victory with a second goalin second-half injury time, the News Agency of Nigeria (NAN) reports.
The Spanish La Liga leaders will meet Japanese champions Kashima Antlers in the showpiece event on Sunday.
Real Madrid, who won the trophy in 2014, dominated early exchanges between the two continental champions.
But the Mexicans created few anxious moments for the Spanish giants on the counter.
Oribe Peralta shot narrowly wide from just inside the area on 12 minutes, before Alex Ibarra valiantly won the ball and charged towards goal on 21 minutes.
But his effort from long range was held by Keylor Navas in goal for the Spanish giants.
Real Madrid mounted considerable pressure on the CONCACAF Champions League winners as the first half progressed.
Lucas Vazquez raced to the byline and delivered a cross from the right to Ronaldo but the Portugal forward’s downward header hit the post.Toni Kroos followed up with an effort a minute later, with Munoz reacting quickly to deny him.
Benzema broke the deadlock on the stroke of half time after slotting in Germany international Kroos lovely through ball.