CHICAGO – While Buster Posey and the San Francisco Giants are fighting for the NL West title, Anthony Rizzo and the Cubs have their own magic number.

Alfonso Soriano hit a two-run homer that landed on Waveland Avenue, and Rizzo added a solo shot Friday, helping Chris Volstad and the Cubs beat the weary Giants, 6-4.

Soriano also had a two-out RBI single in the first as the Cubs (51-80) closed out a miserable August with a second consecutive win. The Cubs, practically locked into fifth place in the NL Central, are hoping to avoid their first 100-loss season since 1966.