In just his fourth major league start, Volstad (3-2), a 21-year-old rookie right-hander, yielded three hits in six scoreless innings to the heaviest-hitting team in the National League.

Closer Kevin Gregg followed three others to record his 25th save this season.

With the win, Florida climbed within 1 1/2 games of the front-running Phillies in the NL East.

Three players knocked in one run each, while Cody Ross and Jeremy Hermida had two hits apiece in the Marlins' seventh win in 12 games against the Phillies in the 2008 season.

Four players had one hit each for the Phillies, who have split their last four games.

Losing pitcher Cole Hamels (9-8) surrendered three runs -- two earned -- and seven hits in 6 1/3 innings with a walk and seven strikeouts.