Steven Duggar kept San Francisco in the game with a run-saving catch and Buster Posey put the Giants ahead with a rare pinch-hit. Posey came through with a two-run double in the eighth inning to rally San Francisco past the Colorado Rockies 6-5 on Saturday night. “What a huge hit,” Giants manager Bruce Bochy said. “It’s nice to have him in that situation coming off the bench. Really, great comeback. Buster delivered in a big way.” Posey batted with two on against reliever Carlos Estevez (1-2) and lined a ball to right-center field to score pinch-runner Kevin Pillar and Austin Slater. Will Smith then got three outs for his 27th save. It was just the second time in his career that Posey put his team in front as a pinch-hitter. He also helped starter Madison Bumgarner avoid a loss on a night the lefty labored through five innings. “I couldn’t throw the ball where I wanted to the whole time I was out there,” Bumgarner said. “It wasn’t terrible, but it wasn’t good by any means.” Estevez faced four batters in the eighth and didn’t get an out before being lifted after his second base on balls. “His pitches were everywhere. He didn’t have his stuff,” Rockies catcher Tony Wolters said.