Medlen (12-12) allowed one run on seven hits and didn't issue a walk in the 95-pitch effort, winning for the third time in three starts.
Andrelton Simmons smacked a two-run homer and Evan Gattis added a solo shot to provide the Braves' scoring.
Mets starter Carlos Torres (3-3) yielded three runs on seven hits over seven full innings.
Daniel Murphy drove in New York's only run.
Theater accidentally screens 'Nymphomaniac' trailer instead of Disney's 'Frozen'
Exploding whale video goes viral on Internet