The A-League has admitted referee Kurt Ams should not have awarded a foul to Bruno Fornaroli in Melbourne City's 2-1 derby win over Melbourne Victory on Friday night, a decision that led to a penalty and goal for the Uruguayan's team.

A-League boss Greg O'Rourke told Fairfax Media on Sunday that the FFA's refereeing department deemed the level of contact by Victory's Corey Brown on Fornaroli "wasn't sufficient to award a foul" based on their post-game review.

The A-League says this incident with Corey Brown and Bruno Fornaroli should not have been awarded a foul. Credit:Fox Sports/Supplied

"It is a subjective decision because there is contact," O'Rourke said. "The question is for them: is the level of contact sufficient to award a foul? In the review after the game they all agreed there wasn't sufficient contact to award a foul."

Fornaroli went down after contact from Brown in the first half with City trailing 1-0 thanks to Keisuke Honda's goal. The referee initially awarded the foul outside the box, but after a VAR review Ams decided contact occurred in the box and awarded the penalty.