Croatia forced the first save of note in the 28th minute when Volkan Babacan held Milan Badelj's volley from the edge of the box.
Turkey paid back a minute later with Ozan Tufan heading Gokhan Gonul’s inviting cross straight at Danijel Subasic from close range.
It was not until the 41st minute that Croatia broke the deadlock thanks to Modric’s moment of magic.
The Real Madrid midfielder ran onto the ball, which was dropping from high in the sky following a half-clearance, and fired an unstoppable volley into the bottom-left corner from 25 yards.
Inspired by the opener, the Croatian played more comfortably and wasted two additional chances to double their tally in the second half, with Darijo Srna hitting the bar with a finely curled free kick and Ivan Perisic also smashing the woodwork.
With time running out, no more goals were scored despite concerted efforts from both sides, which also meant an aggregate 1-0 win for Croatia.
The remaining two teams of Group D, Spain and Czech Republic will meet in an encounter scheduled for June 13.
