Spain won through goals from Aymeric Laporte, Alvaro Morata and Alex Baena. Serbia had Stranhinja Pavlovic sent off in the second-half.
De la Fuente later said, "We played a complete game, focused from the first minute and dominating all facets of the game. With this attitude it is difficult to fail.
"Morata has been recognised in Murcia and Córdoba and I hope that this will happen all over Spain. He is a very important player for Spanish football and the glue that strengthens the unity of our group. It is something that we all have to train for.
"The spirit of 2010 has been recovered and that is something to be proud of. I am excited to experience something like this. The people, the fans are happy when Spain plays and it shows. I said it at the time: we had to recover that spirit of 2010. But it is already there, we just have to feed it and the results help a lot. We must collaborate with each other.
"I see other national teams that are a pleasure when you arrive at a stadium and there are 50,000 Croatians and 12,000 Spaniards. I am excited to see a reaction like that of Córdoba and that of Murcia, which is impressive. I am proud to live in Spain, to be Spanish and to have this fan base. If we get distracted by other things, we enter into a conflict between clubs.... There are no clubs here, it is the national team."