Student protesters and fans clashed during the Varsity Cup game between Shimlas and NMMU in Bloemfontein on Monday.
The protesters, some of whom were armed, walked onto the field when Shimlas were leading 12-7 after 17 minutes.
Having refused to leave the field, they then clashed with fans before the police and university security defused the situation.
Play resumed at 7:40pm, roughly an hour after the match had been interrupted, with Shimlas going on to win 46-19.
'We have contingency plans in place for dealing with match interruptions,' said Varsity Cup CEO Duitser Bosman. 'The possible disruption of matches due to pitch invasion by individuals and groups with other agendas on our campuses, was discussed at length at previous Varsity Cup board meetings.
'A decision was made to respect the challenges universities face. No special rules were put in place to deal with disruptions, as our current competition rules are sufficient.'
VIDEO: Watch student protesters and fans clash
Photo: Conrad Bornman/Netwerk24