Not sure what you're actually referring to. If 2007, we swept four games from the Mets, at home, in August. If it's some other year from an older team I'm just not remembering. There was also a big Milwaukee series in '08 but that was also four, at home.
What's amazing to me is that the late August 2007 series feels like it was when the Phillies took charge of the race, and remains my second favorite series of the whole era (after the '08 NLCS). But it wasn't for very long. They went from 6 games back to 2 games back, but then dropped all the way to 7 games back by September 12. Then they won 6 straight (including three against the Mets in Queens) and it was on.
Like I said, they need to win five straight at some point. May as well try something they've never done before!