Buffon became the most-capped European player of all time this evening as he made his 170th appearance for Italy, albeit in a 3-0 defeat to Spain at the Bernabeu.
The veteran is still the undisputed number one for Juventus and Italy having been part of the latter setup since 1997, and Ronaldo believes that he has improved as the years have progressed.
"The best player in the squad remains Buffon, a real phenomenon... I always had a clear idea, when facing Buffon, that he gives the team a strange sense of security," Ronaldo told La Gazzetta dello Sport.
"He has even become stronger over the years, because he has charisma and just needs a look to send a message. Plus he smiles all the time on the field: he's fundamental."
Buffon is currently fifth on the all-time list of international appearances, 14 behind record holder Ahmed Hassan of Egypt.