Ronaldo is being celebrated after his hat-trick heroics against Atletico Madrid.
But Capello said: “Ronaldo's an extraordinary footballer, but Messi is a genius.
“There are three geniuses in football: Pele, Maradona and Messi. Period. Ronaldo is very strong as he lets you win everything, but Messi is a genius and something else.
“I faced Messi when he was 16 years old and I was amazed. He did the same things he does today but 20 years younger because he was born a genius.
“He invents things that others don't see. Ronaldo has made himself a champion, but not a genius."