The 1972 National League Championship Series was played between the Cincinnati Reds and the Pittsburgh Pirates from October 7 to 11. Cincinnati won the series three games to two to advance to the World Series against the Oakland A's. The Reds became the first team in major league history to advance to the World Series without the best record in their respective league, made possible by the Junior and Senior Circuits each splitting into two divisions in 1969. In the previous three post seasons, the team with the best record in each league advanced to the World Series.
The 1972 NLCS ended with a dramatic ninth inning in the fifth and deciding game. Cincinnati catcher Johnny Bench tied the game with a leadoff home run in the inning, and George Foster would later score the winning run on a wild pitch by Pittsburgh's Bob Moose. The series was also notable as the last on-field appearance by Pittsburgh's Roberto Clemente, who would die in a plane crash on December 31.