Ronaldo's header against the Czech Republic has fired the Portuguese into the Euro2012 semifinals.
"I have not seen all the Euro 2012 matches but Cristiano Ronaldo is having a fantastic competition," Di Stefano told Diario de Noticias.
"He stood out with a great goal against Czech Republic. He is a very complete player, a forward who is there to score goals.
"Pepe and [Fabio] Coentrao are also having great competitions. Pepe is a phenomenal player."