Daniel Oblath, 29, was running with his German shepherd mix, McLovin', in April 2012 when a city parks officer gave him a ticket.
Oblath and his lawyer then showed up at an Environmental Control Board hearing in September, but the city never showed, so the court dismissed the ticket.
The city is still looking for the $100 fee and is fighting to keep dogs on leashes in the park, despite rules that allow off-leash dogs in other large parks before 9 a.m.
The city claims it wasn't required to show up at the September hearing, and there has never been any change in the Battery Park rules.
The case is a part of an ongoing fight between city officials and residents who argue they have been using the park's main lawn as an off-leash area for years.