Modric helped Croatia wrest control of the midfield battle amid a fervent atmosphere at the Parc des Princes before striking an imperious volley into the bottom corner from 25 yards four minutes from half-time.
Cacic's men impressively tightened their grip after half-time but wasteful finishing meant Modric's sensational contribution was a decisive one.
"Luka deserves to be talked about," the coach told a post-match news conference. "Especially after this match.
"This was one of the best performances in Croatian history. He was our leader and he scored a magnificent goal.
"We need Luka in this form because all the team looks different. It looks better, it looks more aggressive."
Another Croatia hero, although for altogether different reasons, was centre-back Vedran Corluka.
A painful clash with Turkey striker Cenk Tosun left him with a bleeding head wound shortly after the half hour.
The Lokomotiv Moscow man was stitched and bandaged up and returned to the action before having further dressing applied at half-time.
Corluka went off the field in pain twice more but was present at the final whistle to celebrate before a buoyant Croatian contingent at the home of Paris Saint-Germain.
"Corluka had some stitches on the top of his head. He has shown so much courage," said Cacic before giving a graphic description of his player's struggles.
"He did so many headers even though he had those stitches and he was bleeding. It was worse and worse after every header but I congratulate him.
"He is a fighter and he stayed until the end even though it was not comfortable."
Cacic added: "We must secure our place in the next round. I said to my players I am more afraid of the Czech Republic than Turkey.
I want to focus on this next match straight away It is important for the whole team to stay focused.
"As the Croatian team, we can expect only positive results from all the matches."