Cincinnati, 91-59, has yet to clinch the National League Central Division title but owns a good enough record to assure the Reds of at least a wild-card spot. The Washington Nationals also wrapped up a post-season berth with a win later in the evening against the Los Angeles Dodgers.
Cincinnati broke open a scoreless game with a five-run rally in the seventh inning. The Red got six of their nine hits on the day in the rally.
The entire rally was charged to Cubs reliever Manuel Corpas (0-2), who pitched one inning.
With one out, Denis Phipps, Ryan Hanigan, Didi Gregorius, Joey Votto and Xavier Paul had consecutive singles to account for three runs. One out later, Rodriguez lined a shot into the gap in left-center for his first double and first RBI in the major leagues.
The Cubs got on the board with singles runs in each of the last three innings with Anthony Rizzo knocking in runs in the seventh and ninths and Wellington Castillo hitting a home run in the eighth.