On September 1, , the Pirates fielded what is believed to be the first all-black lineup in the history of the league. Oliver played first base, joining second baseman Rennie Stennett, center fielder Gene Clines, right fielder Roberto Clemente, left fielder Willie Stargell, catcher Manny Sanguillén, third baseman Dave Cash, shortstop Jackie Hernández and pitcher Dock Ellis in the starting lineup. Oliver ended the season with a .282 average, including 31 doubles (8th in the NL), seven triples (10th), 10 sacrifice flies (2nd), and five hit-by-pitches (good for 9th in the league). After beating the San Francisco Giants in the 1971 National League Championship Series, the Pirates won the World Series, beating the Baltimore Orioles in seven games with Oliver as their regular center fielder.