Buster Posey’s 21st homer and a Brandon Crawford sacrifice fly were enough offense for Peavy to beat Josh Collmenter and inch the Giants closer to a playoff spot. The Giants’ offense, which hummed during the recent run of success, ground to a near-halt in the face of some excellent pitching after taking a 9-0 lead against the Dodgers on Friday night. The Giants had scored four runs over 31 innings when Buster Posey broke a scoreless tie with his 21st home run, a high drive to left with one out in the fourth that cleared the glove of a leaping Ender Inciarte. The 1-0 lead held until the sixth, when Owings hit a one-out triple and Pollock smashed a single just past a diving Pablo Sandoval. Mark Trumbo’s double play sent a 1-1 game into the seventh, when the Giants untied it on singles by Hunter Pence and Travis Ishikawa and rawford’s sacrifice fly. After Blanco flied out to make it 4-for-26, the Giants had a frustrating run of at-’em balls: four straight ropes that resulted in four outs, including liners by Joe Panik and Posey, and a Hunter Pence double play that was inches from a double inside third base.