Gorkys Hernandez hit a one-out double off Chad Qualls, and after Cory Gearrin struck out — yes, Gory Gearrin, the winning pitcher — Span stepped up and collected his third hit in seven at-bats. Six Giants relievers combined for eight scoreless innings (three by Gearrin) after Matt Cain threw the first six. In extra innings, Buster Posey threw out two runners trying to steal, and pitcher Jeff Samardzija was summoned to pinch hit — he struck out to end the 11th. [...] the eighth inning, the Giants seemed destined to be burned by Mark Reynolds’ three-run homer. The ball sailed softly into right field to score Belt and put the Giants in position to take the lead, but Jake McGee struck out Hernandez and Nick Hundley. Posey opened the inning with a single. Cain opened with five scoreless innings but scuffled in the sixth. The Giants scored the first run back in the third on Span’s two-out single. Another threat came an inning later when the Giants chased Jeff Hoffman, who gave the Rockies a much-needed start in the wake of several abbreviated assignments by his rotation mates. In the inning, pinch-hitter Austin Slater legged out an infield single and was replaced by a pinch-runner, pitcher Ty Blach.