The Bianconeri goalkeeper was quick to salute his Blancos counterpart for pulling off three stunning stops during their sides' Champions League showdown.
The two European giants drew 2-2, with Casillas making a number of excellent saves throughout the match to earn his side a point.
The two men have been hailed as the world's top goalkeepers for a decade now, and Buffon was left in no doubt as to the brilliance of his Madrid counterpart.
"Casillas was decisive," the World Cup winner told Futbol. "He had a great game and made three critical interventions."
Despite the draw, Juve dropped to the bottom of Group B, but it is just one point behind Galatasaray and Copenhagen, with games to come against both.
Consequently, Buffon remains optimistic that the Bianconeri will make the last 16.
"We are in a difficult group, but we still have a good chance of getting through," the 35-year-old shot-stopper stated. "Copenhagen and Galatasaray are both doing well and however far Real Madrid get in the competition, they have great quality.
"We are in a tough group, but we must keep on fighting."