Top-of-the-table Canada kept up their unbeaten record in the Olympic baseball with a 2-0 win over Greece.
Japan, who had a famous win over Cuba on Tuesday, were brought back to earth when they were upset 9-4 by Australia.
Starting pitcher Naoyuki Shimizu said he was still tired from the Cuba game but admitted he had underestimated the Australians.
Cuba kept pace with a 10-2 victory over Taiwan, while Holland kept their medal hopes alive by beating Italy 10-4.