Harrison (1-0) allowed three hits and two walks while striking out 11 over 6.1 scoreless innings to earn the win in Monday's 4-1 victory over the Reds.
Harrison fared respectably in his MLB debut in Philadelphia last Tuesday, but he was dazzling in his home debut against a formidable lineup. He allowed just two runners to get into scoring position on his watch. Harrison has a 16:3 K:BB over 9.2 major-league innings and should be able to stick in a Giants rotation that has only two other full-time starters (Logan Webb and Alex Cobb). The rookie is tentatively projected for a road start in San Diego this weekend.