Jake Peavy had another strong outing, Buster Posey homered and the San Francisco Giants gained a game in the NL West race with a 2-1 victory over the Arizona Diamondbacks on Tuesday night.Arizona Diamondbacks starting pitcher Josh Collmenter throws in the first inning during a baseball game against the San Francisco Giants, Tuesday, Sept. 16, 2014, in Phoenix.San Francisco Giants starting pitcher Jake Peavy throws in the first inning during a baseball game against the Arizona Diamondbacks, Tuesday, Sept. 16, 2014, in Phoenix.San Francisco Giants Hunter Pence comes home to score on a sacrifice fly out on a ball hit by Brandon Crawford in the seventh inning during a baseball game against the Arizona Diamondbacks, Tuesday, Sept. 16, 2014, in Phoenix.Arizona Diamondbacks shortstop Chris Owings turns the double play while avoiding San Francisco Giants Pablo Sandoval (48) in the second inning during a baseball game, Tuesday, Sept. 16, 2014, in Phoenix.