After eight innings of missed opportunities, the National League's most potent road offense finally showed up. The Giants scored two runs in the top of the ninth inning at Minute Maid Park to come from behind for a 3-2 victory over the Houston Astros on Tuesday. Brandon Belt scored the tying run on a Joaquin Arias double, and Arias scored the go-ahead run two batters later on Hector Sanchez's pinch-hit single