The Spanish side beat the Italian champions, who had a player sent off, 2-1 at the Bernabeu this evening, leaving them five points clear at the top of group B.
The goalkeeper told AS: "We have taken a very important step to ensure qualification [to the knockout stages], it was not easy, but the first step has been taken.
"Nine points from three games, and Juventus have to not lose. It hurt them to have one player less, because they had to retreat even further back."
Juventus's defeat has dropped them down to third in the group.