Scruggs greeted reliever Jorge Marban with a first-pitch, three-run blast over the replica Green Monster in left field.
Left-hander Chris Narveson, making his third appearance and first start, went three scoreless innings for the Marlins, scattering four hits with one walk and one strikeout. Narveson got Red Sox slugger David Ortiz to ground into inning-ending double plays in the first and third.
"It is Spring Training," Narveson said.