A season-opening clash featuring All Blacks stars Beauden Barrett and Kieran Read was scrapped on Tuesday after dozens of people tested positive for the coronavirus in Japan's Top League rugby.
The outbreak comes during a surge in cases which has prompted a state of emergency in the greater Tokyo area, just six months before the capital is scheduled to host the postponed 2020 Olympics.
The Top League said 44 people from three teams - Toyota Verblitz, Suntory Sungoliath and Canon Eagles - tested positive in pre-season screening, without revealing any identities or how many were players or staff.
As a result, "Japan Rugby Top League chairman Osamu Ota decided to cancel two matches (involving the three clubs) after discussions with stakeholders", a statement said.
The cancelled matches include the opening-day match-up between Read's Toyota Verblitz and Barrett's Suntory Sungoliath on Saturday.
The games will not be rescheduled, but will be recorded as 0-0 draws with the teams awarded two points each. Tickets will be refunded, the league added, apologising to fans.
The rugby cluster comes as Japan battles a third wave of virus infections that has caused a record spike in cases.
The worsening situation appears to have hardened public opinion against holding the Olympics this summer, with just over 80 percent of respondents in a poll published on Sunday favouring further postponement or outright cancellation.