Economic Freedom Fighters supporters had gathered in a hall at the university, with Malema having arrived, the state broadcaster reported.
Shortly before the event was meant to get underway, ANC supporters made their way into the hall, disrupting the event.
University academics attempted to calm the situation but ultimately Malema and other EFF officials accompanying him were forced to leave the venue.
Malema then addressed supporters from the steps of the hall.
“They [the ANC members] are very few and we will find that some of them are not even students,” he said.
“[It] is a rented crowd paid with yellow t-shirts.”
The SABC reported that the ANC said it would investigate the incident, and it did not tolerate its members disrupting other parties’ events.
The Electoral Commission of SA said all parties should promote political tolerance at all times.