The Giants sent Ramon Ramirez (2-2) to the mound in the ninth after scoring three runs in the eighth to tie the game. Nick Hundley led off with a double down the left-field line, moved to third on a sacrifice bunt and scored the go-ahead run on Gonzalez's base hit up the middle. Gonzalez advanced to second on a wild pitch and crossed the plate on Venable's single to right to account for the final margin.
Mat Latos gave up two runs -- one earned -- on three hits in a six-inning start for the Padres, who have won a season-high five straight games. Erik Hamren (1-0) recorded the final out in the eighth to pick up his first victory in the majors. Heath Bell got his 35th save.
Matt Cain allowed five runs -- three earned -- on six hits over seven innings for San Francisco, which has lost six of eight.