Croatia topped Group D after a fantastic victory over Vicente del Bosque's side. It didn't get off to the best of starts, with Alvaro Morata's opener seven minutes in.
However efforts from Nikola Kalinic, and a late one from Ivan Perisic secured another three points for Cacic, who praised his side's efforts.
Cacic told uefa.com that it was a "important result" for Croatia to beat a "really strong team," but it isn't "about one match." He believes they can "play anyone" and be "successful."
He continued, saying the opportunity to change five players and "play the next round" with "fresh players," having had the chance to "test" young players, makes the result "even more important."
Success of the team
Along with Luka Modric, Inter Milan's Perisic has been a shining beacon in this Croatia team so far, and that showed securing the man of the match award against the Spanish. However, Perisic said that it is all about the efforts and success of the team.
He said that "what matters" is the "success of Croatia," adding that he is hopeful they can go a "long way." He continued, saying that he is part of a "great group of guys" who will be looking to fix "some minor mistakes" ahead of the next game, but he is "really proud" to be part of the team.
Perisic was eager to heap the praise on those around him, saying that "each player" in the team "deserves" to be there and everyone can "count on" each other.
Talking about the game, he said that coming back from a goal down, was a "testament to the character" of the team, who are "very motivated" to "keep moving forward."