Logan Webb found himself in the middle of a playoff race, and was up to the challenge. The 22-year-old right-hander survived a rocky start and pitched five innings to win his major league debut, leading the San Francisco Giants to an 11-6 victory over the Arizona Diamondbacks on Saturday night. Brandon Belt hit a grand slam and tied a career high with six RBIs as the Giants won their third straight game and sixth in the past seven to continue their surge into serious National League wild-card contention.