SAN FRANCISCO — The Giants hope there are many more days like the second Friday in May two years ago. For one, they won. The final score was 8-2, over the Cardinals, at Busch Stadium. But it took a late five-run rally to blow the game open. For the first five innings, they were mostly flummoxed by a 25-year-old pumping fastballs that touched 104 mph. They scratched three runs across but mustered just three hits, the opposing starter only forced from the game because of limits on his workload. Not quite three years later, that pitcher signed a four-year, $44 million pact with the Giants that wa…