He then was hired as the third-base coach for the Boston Red Sox, serving for 2½ seasons. Working under skipper Darrell Johnson, Zimmer's tenure included a memorable event during Game 6 of the 1975 World Series. Boston had the bases loaded and none out in the home half of the ninth inning. The score was tied. A soft fly to left field was too shallow to score the winning run, but baserunner Denny Doyle thought Zimmer's shouts of "No! No! No!" were actually "Go! Go! Go!" He ran for home, and was thrown out at the plate. That play, and Dwight Evans' brilliant catch off Joe Morgan in extra innings, set up Carlton Fisk's classic, game-winning home run.