The Video Assistant Referee system was used for the first time in World Cup history on Saturday, when France were awarded a penalty against Australia in Kazan.
Antoine Griezmann went down after a tackle in the penalty box in the second half of the Group C fixture.
The referee did not award a spot-kick but the VAR officials ruled after a review that it was a penalty and Griezmann gave France a 1-0 lead.
Minutes later Australia drew level through a spot-kick of their own although it was awarded by the referee, with Mile Jedinak coolly beating Hugo Lloris.
VAR has been used to varying degrees of success in Serie A and the German Bundesliga, while FIFA used the system at the Confederations Cup in Russia last year.
FIFA director of referees Massimo Busacca admits the system has been rushed in for the World Cup, but insists officials are ready and VAR will help referees make better decisions in Russia.