Mitchell Moses went off injured in the first half and Parramatta needed a drop goal from Clinton Gutherson to finally see off Canberra.
No fans will be permitted and games will be played at neutral venues, but Super League will return on August 2.
Melbourne Storm thrashed New Zealand Warriors 50-6, but the victory came at a cost as Cameron Munster suffered a serious knee injury.
Penrith Panthers moved to the top of the NRL standings thanks to a 18-12 victory over South Sydney Rabbitohs.
James Graham is poised to return to St Helens and end his time in the NRL.
Melbourne Storm could move their home against New Zealand Warriors to Sydney.
Manly Sea Eagles continued their excellent form in the NRL but saw their injury woes deepen.
After the decision to sack coach Stephen Kearney, the New Zealand Warriors hierarchy could be facing a revolt from the players.