Jenrry Mejia, making his season debut, combined with two relievers on the shutout in the opener of a day-night doubleheader.
Murphy hit a solo homer in the first and a two-run blast in the second. He added RBI singles in the seventh and ninth innings. Ike Davis also had a three-run homer in the ninth, during which the Mets piled on six runs.
Mejia (1-0) gave up seven hits in seven innings in a bid to ignite his major league career. He had thrown only 16 innings in the big leagues since undergoing elbow surgery in May, 2011. This was just the second victory of his career, which consists of seven starts and 32 relief appearances scattered over four seasons.
Jordan Zimmermann (12-6) gave up five runs on six hits in 6 2/3 innings to take the loss. It was his second straight setback at home after he had gone 22 straight starts without one.