Kovac's men are still in contention to advance to the round of 16 at the FIFA World Cup after easing past 10-man Cameroon 4-0 in Group A action in Manaus.
The win moved Croatia to within a point of final-round opponent's Mexico and Brazil, and Kovac said the performance showcased the country's true value after their controversial loss in the World Cup curtain raiser last week.
"Everything we prepared before the game, that's what happened," Kovac said post-game.
"We searched, we possess, we created chances and took advantage.
"We showed our true face after an unfortunate defeat and great game against Brazil.
"We have also prepared tactically excellent, gave us the strength and faith and hope."
Wolfsburg pair Ivica Olic and Ivan Perisic were on the scoresheet but star striker Mario Mandzukic played a leading role upon his return from suspension, scoring twice as Croatia heaped the pressure on Mexico, who they will face on Monday.
However, the Bayern Munich man refused to take credit for the emphatic triumph: "I felt good, I was preparing intensively.
"I had a little more time since I have not played the first game so I worked extra.
"But I am not responsible for this victory, the whole team played superbly. Goals came as a reward."
