In the 1973 American League Championship Series, in which the A's defeated the Baltimore Orioles, he led off Game 2 with a home run, and won Game 3 with a leadoff home run in the 11th inning; in Game 7 of that year's World Series against the New York Mets, both he and Reggie Jackson hit two-run home runs in the third inning off Jon Matlack—the only two home runs Oakland would hit the entire series. The A's took a 4–0 lead and went on to win the game and repeat as world champions; Campaneris caught Wayne Garrett's pop-up for the final out of the Series. In he broke Jimmy Dykes' franchise mark for career at bats (6023), and in he broke Dykes' mark for games played (1702), as well as Al Simmons' Athletics record of 1827 career hits.