The Marlins are 26-22 since welcoming the Mets to town on May 31.
The returns from injury of sluggers Giancarlo Stanton and Logan Morrison and starting pitchers Henderson Alvarez and Nathan Eovaldi have aided the run.
"We've played a lot better since we got our guys back and healthy," Marlins manager Mike Redmond said. "I think that's made a big difference.
"We've done a good job of controlling what we can control, and that's ourselves and focusing on that."
But the Marlins had enjoyed moderate success against the Mets even before May 31, splitting six games against New York, including their first series victory from April 29-May 1.
Said Redmond of his club's 8-3 record against the Mets: "It's probably more of a coincidence."
The two teams have played two of the most memorable extra-innings games this season, battling for 15 innings on April 29 at Marlins Park and 20 innings on June 8 at Citi Field. Miami won both contests.
The Marlins may have the upper hand between the two, but Redmond is not taking the remaining eight games against their National League East rivals lightly.
"We've had some great games against the Mets," Redmond said. "We know that every time we play them, or any team in our division, that it's going to be a battle. They're not going to quit. We're not going to quit. It's been fun. It's been a fun little series."