Tommy La Stella and Brandon Belt hit three-run homers and San Francisco pounded Chicago for its sixth straight victory. La Stella finished with three hits, including a double, five RBIs and scored three runs to help surging San Francisco improve to a major league-best 92-50. La Stella's home run off Tommy Nance in the fifth thudded off Wrigley's right-field videoboard and capped a six-run rally that allowed San Francisco to pull away.