The WNBL finals have been thrown into chaos after a COVID-19 outbreak forced the postponement of game two of the semi-final series between the Canberra Capitals and Perth Lynx.

The Capitals were scheduled to host the Lynx in Canberra on Sunday with the winner of the best-of-three series due to face the Boomers in the championship decider starting in Melbourne on Saturday April 2.

But the WNBL announced hours before tip-off that a number of positive cases had been detected in Canberra's camp, along with other players who were symptomatic and awaiting test results.

Due to ACT government COVID guidelines, affected athletes cannot leave isolation until they produce a negative PCR test, leaving the Capitals unable to field the seven players required to hold the game.

Shortly after the postponement was announced, the league advised that the Lynx-Capitals series would revert to a best-of-two series with the winner determined by a points spread over the two games as per FIBA rules.

With the Lynx winning the opening game of the series 91-77 in Perth on Thursday, the Capitals need to win game two by 15 points in order to qualify for their 12th WNBL grand final.

The Boomers punched their ticket to the championship round after completing a 2-0 series sweep over the Adelaide Lightning with a 61-49 victory in Saturday's game two in Adelaide.

AAP