Utrecht secured a 1-0 victory over Kozakken Boys at the 5,000-capacity Sportpark De Zwaaier, after which travelling fans rushed onto the field at full-time.
The two groups of supporters met on the pitch and a large confrontation broke out, prompting security to step in.
Separated only by the pitchside advertising board, the fans began hurling objects, including a wheelie bin thrown from the stands.
Dutch football journalist Jeroen Kapteijns posted video of the scene on social media, writing: "Things get pretty out of hand after the final whistle in Werkendam, with black-jacketed folks going at each other."
He added: "Such a shame for cup football to have this kind of brainless idiots." and "The black jackets on the pitch come from the FC Utrecht section and attack the supporters of the home team."
Utrecht's win came via a first-half goal from Nikolas Panagiotou, advancing them to the second round of the KNVB Cup.
