Giancarlo Stanton and Placido Polanco also drove in a run each for the Marlins, who dropped the first two games of the four-game series with the Mets.
Mike Dunn pitched the ninth for his second save in place of Steve Cishek, who pitched two innings and took the loss in Tuesday’s 4-2 loss to New York.
Dunn issued a lead-off single to John Buck before retiring the next three batters to end the game.
Alvarez (2-1) allowed two runs and six hits in 7 1-3 innings. He is 2-0 with a 1.33 ERA in his last four starts.
Marisnick homered off of Jenrry Mejia (1-1) in the second inning to give the Marlins a 1-0 lead.
Source: Associated Press