The Pirates overcame an early three-run deficit to take the lead, but could not hold on for what would have been their fifth straight win.
Jason Grilli (0-2) took the mound in the seventh for his first inning of work and retired the first two men he faced. Luis Valbuena, however, walked on a 3-2 pitch and Rizzo then hit a 1-0 offering from Grilli over the wall in right.
Pittsburgh put one runner on in each of its last three at-bats, but was eventually shut down by the Chicago bull pen.
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