Jupiter had a three-run first inning and pulled away late in the game as the Hammerheads blanked the Mets 7-0 at Tradition Field on Friday night.
The Mets dropped their second straight game after winning five consecutive games.
Hansel Robles allowed four runs over seven innings and suffered the loss. Shawn Teufel allowed two runs in the eighth inning and Bret Mitchell gave up a run in the ninth.
The Mets offense was limited by Jupiter starter Scott Lyman, who pitched six scoreless innings.
The Mets will look to bounce back on Saturday as they visit the Jupiter Hammerheads at 5:35 p.m. Alex Panteliodis is the scheduled starter for the Mets.