The Mariners have maintained top position on the WA Premier Cricket ladder after a first innings win over Joondalup.
Rockingham-Mandurah posted 184 on the first day and needed four wickets quickly on the morning of the second day of the game.
Adam France claimed three wickets to run through the Joondalup lower order to dismiss them for 157.
The Mariners batted a second time and were 7/133 at stumps.
Next week Rockingham-Mandurah are back at home hosting Willetton in the last round of the regular season, a 50-over fixture.