Buck's blast in the second inning off struggling Phillies starter Roy Halladay gave the Mets a 3-0 lead and set the tone for the game.
Harvey (2-0) followed up a seven-inning, one-hit performance in his previous start with another solid effort, limiting the Phillies to one run on three hits while striking out nine and walking two.
Phillies ace Halladay (0-2), meanwhile, was hit hard in his second straight outing, yielding seven runs on six hit over four full frames.
Justin Bieber crashes Drake Bell's album release party
Chipotle plans first price increase in 3 years