Kolarov's 56th minute attempt was one of the few notable moments of a match that saw both teams struggle to create scoring chances.
With three points in their kitty from the first match of the group, Serbia will aim to improve their form ahead of sterner tests against Brazil and Switzerland.
Serbia, who enjoyed a distinct height advantage, were too reliant on the long ball approach. But lack of creativity upfront prevented them from exploiting their dominance in the air.
The Serbian defence, however, was well organised and offered the Costs Rican forwards very little space to exploit.
Serbia's Branislav Ivanovic became his country's most capped player with 105 appearances, but he and his fellow defenders had a comfortable outing as the Europeans enjoyed the majority of possession in the first half, reports Xinhua news agency.
However, Serbia created few clear cut chances, though Aleksandar Mitrovic should have done better with a close range effort comfortably saved by Costa Rica goalkeeper Keylor Navas.
Costa Rica struggled to get out of their own half until just before the break when Marco Urena fired over the bar and Francisco Calvo sent a right-foot effort wide of the post to end what was generally a drab first 45 minutes.
The Serbs began the second half in positive mood and only a fine save from Navas denied Mitrovic after the big striker had been put clean through on goal by Sergej Milinkovic-Savic.
However, even Navas was unable to keep out Kolarov's free kick in the 56th minute as the Roma left back curled the ball over the defensive wall and into the corner past Navas's left hand, with the Costa Rican keeper at full stretch.
Costa Rica failed to react to the strike and Navas saved another certain goal when he did just enough to deflect a cross from Tadic away from Felip Kostic who would have had a tap in.
The game ended with VAR being used deep into injury time when referee Malang Diedhiou decided Serbia striker Aleksandar Prijovic only deserved a yellow card and not a red after catching Johnny Acosta in the face with a trailing arm.
(This story has not been edited by Social News XYZ staff and is auto-generated from a syndicated feed.)
