“Ayedelotte was knocked out of the box in the fourth inning and Sales was put in to pitch.” Harrisburg Independent, September 22, 1882, p1.
Previous earliest use (Dickson Baseball Dictionary, 3rd edition, 2009):
1ST USE. 1883. “The curve delivery in base ball pitching was the greatest change ever introduced into the game; and in these days, when an old-time straight pitcher would be knocked out of the box in an inning, there are a good many claimants for the credit of originating it” (Philadelphia Press, Aug. 20).