The 1-0 win sees La Roja qualify for the round of 16.
De la Fuente later said: "I think the same as yesterday, I'm very proud of the result and the way we won the match. But this is a very difficult competition and as you go forward the opponents start to know you and become more competitive. We have to keep these feelings, I still think that there is no one better than us but we must never lower our level and continue to work in this way."
On his first-half clash with Italy coach Luciano Spalletti, he continued: "Nothing, it's football stuff. There are moments when your head is a bit hot, but nothing happened. I admire Spalletti a lot but I don't think that the difference between the two teams was only physical, in my opinion we were superior in everything.
"Having said that, we have excellent possibilities to improve further."
De la Fuente added: "Yes, I think it was the best Spain I've ever led. Tonight we were more complete and I never tire of saying that Spanish football is the best in the world. I want to highlight the quality of this generation of players, for me they are the best in the world."