As a player-manager, he led the Senators to two seventh-place finishes, and in his second managerial stint led the Red Sox to the 1912 World Series title. His success was short-lived, as he had a falling-out with his teammates and resigned midway through the 1913 season. His successor, Bill Carrigan, would win two more World Series titles for the Sox. Stahl died in Monrovia, California at age 43.
Stahl was not related to Red Sox teammate Chick Stahl, despite contemporary accounts erroneously listing them as brothers.