Osaka Prefecture says a record 666 new cases of the coronavirus were confirmed on Saturday.
The number has topped 600 for three straight days, and exceeded Tokyo's number for five straight days.
The cumulative number of cases found in the prefecture reached 54,096.
The total number of new cases confirmed across Japan on Saturday was 2,775, including 446 in Tokyo, 206 in Hyogo, northwest of Osaka, 149 in Saitama, north of Tokyo, and 136 in the northeastern prefecture of Miyagi.
This brings the total number of infections in the country to 484,017, including 712 on a cruise ship.