George Springer hit a tie-breaking solo homer in the eighth and the Houston Astros rallied past the San Francisco Giants 4-3 on Wednesday night. He sent Jeremy Affeldt's (0-2) pitch over the yellow line in left-center. Chad Qualls (1-2) threw a perfect eighth for the win and Luke Gregerson pitched the ninth for his eighth save. Buster Posey had three hits and three RBIs, putting the Giants ahead 3-1 in the fifth with a two-run homer after he gave San Francisco a 1-0 lead in the first on a single.