Real scored twice in the final 15 minutes to see off Sporting 3-1.
"It was another difficult game and it was hard for us to pull through, but we did in the end. We have to win the remaining games come what may, and they'll all be hard," said Marcelo.
"We have many forwards capable of scoring several goals and we want more. Cristiano has no limits and we have to take advantage of all the strikes he nets for us. The team is strong both physically and mentally."