Buster Posey broke a sixth-inning tie with an RBI single and Steven Duggar capped a big game with a two-run double in a five-run seventh, propelling the San Francisco Giants to a 7-1 victory over the Oakland Athletics in the opener of a three-game interleague series Friday night in San Francisco. Madison Bumgarner (3-3) pitched into the seventh inning and right-hander Reyes Moronta escaped a bases-loaded, no-out jam to protect a one-run lead, as the Giants prevailed in the first of six straight games they'll play against their San Francisco Bay Area rival sandwiching the All-Star break. After Oakland's Chad Pinder hit his 10th home run of the season, a solo shot, in the fifth inning to offset a Giants run that scored on an Edwin Jackson balk one inning earlier, Posey looped a two-out single to score Duggar in the sixth to give San Francisco the lead for good at 2-1.