[Reuters] Walker wobbles but leads D-backs over Giants - The 24-year-old right-hander and the D-backs fell behind 4-1 midway through the fifth inning, which Walker attributed to the nerves involved in making his first start since being acquired in the offseason from the Seattle Mariners. Started off a little rough," he said. "I was kind of amped up, but the last three innings were really good." Said Arizona manager Torey Lovullo: "When his back was against the wall, he made pitches and kept us in the game. He threw some quality pitches all night. He gave us a chance to win, which is what we want from our starters.