The Under-21 boss was delighted with his side's 3-0 win over Netherlands but has warned the toughest tests are yet to come in Israel
La Roja convincingly strolled past Cor Pot's side thanks to goals from Alvaro Morata, Isco and Alvaro Vazquez to secure Group B's top spot and advance to the semi-finals of Euro 2013.
Lopetegui was thrilled at his side's displays thus far in the tournament in Israel, but has urged his charges to focus on the next task at hand.
"We are happy with the three points and we are playing very well," the 46-year-old told reporters after the match.
"But we are thinking on a game-by-game basis and now we are looking towards our next match, which is the most important yet."
Spain will face Norway in the semi-finals on June 15, while Netherlands prepare to lock horns with Italy the same day, having finished second in Group B.