There is an upshot to starting a game with Buster Posey and Michael Morse on the bench. You have Buster Posey and Michael Morse on your bench. Giants manager Bruce Bochy feels better about his lineup depth this season, which is why he felt he could afford to rest his cleanup man and power-hitting left fielder Thursday afternoon. It’s also why he felt comfortable leaving Brandon Belt at first base and not wedging Posey’s bat into the lineup there. It all worked out for the Giants in the end. Belt hit a home run to provide an early lead, and when Arizona nudged in front with a couple home runs against Tim Lincecum, Bochy had all his weapons ready to deploy in the late innings. How does this sound: 2 for 2 with a home run, a walk and four runs scored. That’s what the Giants bench did to help them draw even, and Angel Pagan crushed a tiebreaking three-run home run as they trotted off with an 8-5 victory at Chase Field. The Giants won three of four in their season-opening series against the Diamondbacks, with their high-powered offense rallying for a pair of those wins. Brandon Hicks’ first at-bat as a Giant resulted in his first career pinch home run. That solo shot came in the seventh inning, and Bochy hit the red button to empty the rest of his bench in the eighth.