Thousands of Greek protesters marched in central Athens on Friday against new reforms, including restrictions on the right to strike.
Parliament is set to approve them next week in return for bailout funds from international creditors.
The shutdown of the Athens metro, used by some 938,000 commuters daily, caused traffic gridlock in the city of 3.8 million people.
Ships were unable to sail as workers went on strike, and state-run hospitals had to rely on reserve staff.
More work stoppages are expected on Monday.