Saturday's Super Rugby Unlocked fixture between the Lions and Cheetahs at Ellis Park in Johannesburg, South Africa, has been called off.
The cancellation happened after two players from the Lions squad tested positive for COVID-19.
"The decision was taken as part of prescribed precautions advised by the National Institute for Communicable Diseases (NICD) to limit the risk of further infection in the rugby community," said SA Rugby CEO Jurie Roux in a statement.
"Containing the spread of the disease is a national imperative and this first impact on the rugby schedule is a stark reminder of how vigilant our community has to be and how rigorous we must be in following the rules.
"Safety comes first, and although it is extremely disappointing for all concerned, it is a reminder to our teams and players of the role their actions will play in avoiding the risk of more cancellations."
Saturday's other Super Rugby Unlocked fixture between the Bulls and Sharks at Loftus Versfeld in Pretoria has remained unaffected.