1972 National League Championship Series

Cincinnati won the series, 3–2.

The Reds got a first-inning homer from second baseman Joe Morgan to take a short-lived 1–0 lead. But Pittsburgh bounced back with three in the bottom of the inning, highlighted by an RBI triple from Al Oliver and an RBI double from Willie Stargell. Pittsburgh never looked back, getting a two-run homer from Oliver in the fifth and coasting to the win behind the strong pitching of Steve Blass. The frustrated Reds ultimately stranded 11 baserunners, and their manager Sparky Anderson was ejected in the fourth inning. The time of game was a brisk 1 hour and 57 minutes.

Cincinnati bounced back to even the series in Game 2. Pittsburgh starter Bob Moose allowed five consecutive hits to start the game. Bobby Tolan and Tony Pérez both hit two-run doubles to give the Reds a 4–0 lead and chase Moose. The Pittsburgh bullpen stopped the Reds offense, though, and the Pirates came back to make it a 4–3 game with single runs in the fourth, fifth and sixth, as Milt May, Roberto Clemente and Dave Cash picked up RBIs. Joe Morgan homered in the eighth to give the Reds a crucial insurance run, and Cincinnati reliever Tom Hall finished a long and strong relief stint to get the victory.

The series moved to Cincinnati and produced a tense, low-scoring contest. Cincinnati's Darrell Chaney and Bobby Tolan hit RBI singles in the bottom of the third to give the Reds a 2-0 lead. In the fifth, Pittsburgh catcher Manny Sanguillén homered to cut the lead in half, and Rennie Stennett tied the game at 2 in the seventh with an RBI single. The Pirates scored the go-ahead run in the eighth on a groundout by Sanguillen. Pirates closer Dave Giusti, came on in the eighth to shut the door on the Reds and earn the save.

The Reds evened the series in Game 4 behind a sparkling two-hitter from left-handed hurler Ross Grimsley. The Reds scored three runs off Pirates starter Dock Ellis, aided by Pittsburgh errors in the first and fourth. Grimsley singled in another run in the sixth and the Reds eventually added three more. The run support was more than enough for Grimsley as he held the typically potent Pirates' offense in check. He yielded just two hits, both by Roberto Clemente. Pittsburgh got its lone run on a seventh-inning homer by Clemente.

Game 5 proved to be one of the more memorable postseason contests in baseball history. After rain delayed the start of the game for 90 minutes, Pittsburgh took an early 2–0 lead with second-inning RBIs from Richie Hebner and Dave Cash. The Reds got one back in the third on an RBI double by Pete Rose. But Pittsburgh inched further ahead with another run-scoring hit from Cash in the fourth. César Gerónimo cut the Pirates' lead to 3–2 with a homer in the fifth. The Pirates held onto their 1-run margin until a dramatic bottom of the ninth.

With the defending World Series champion Pirates three outs away from returning to defend their title, Reds catcher Johnny Bench hit a 1-2 backdoor changeup off Pittsburgh closer Dave Giusti over the right field wall for a home run to tie the game. Tony Pérez singled and was replaced by pinch-runner George Foster. Denis Menke followed with another single as Foster moved to second base. With the count 2-0 on Geronimo, Giusti was replaced with Game 2 starter Bob Moose. Geronimo's fly ball out advanced Foster to third base, but Moose induced shortstop Darrell Chaney to pop out as Foster stayed at third. Just when it looked like Moose may wiggle out of a tough two-on, no out situation, he uncorked a wild pitch to pinch-hitter Hal McRae scoring Foster with the winning run, as the hometown fans and the Reds players celebrated a return to the World Series to face the Oakland A's. It was only the second time a postseason series ended on a wild pitch, the other being the 1927 World Series in which the Pirates lost to the Yankees in a four-game sweep.