With one out in the bottom of the 10th, Devin Mesoraco reached base on an infield hit against Greg Burke (0-3) and went to second on Derrick Robinson's single to right.
Sean Henn took the mound, and with New York's outfield playing in, Choo (3-for-6, two RBI) bashed a pitch off the left-field wall for the decisive blow.
Manny Parra (2-3) earned the victory for the Reds, who claimed at least a National League wild-card spot with the victory and remained tied with Pittsburgh two games behind NL Central-leading St. Louis.
Lucas Duda cracked a solo homer and drove in two runs for the Mets, who dropped the opener of a three-game series.
Notable deaths of 2014 [PHOTOS]