1941 – Jonas Gaines of the NNL Baltimore Elite Giants beats the NAL St. Louis Stars 3-1 in an interleague game at Hammond, Indiana, striking out 19 opposing batters, an all-time high for Negro league pitchers. However, since it was an interleague game, is will not be recognized as a record for any particular league.

This Day In Baseball

On August 14, 1941 — 1941 – Jonas Gaines of the NNL Baltimore Elite Giants beats the NAL St. Louis Stars 3-1 in an interleague game at Hammond, Indiana, striking out 19 opposing batters, an all-time high for Negro league pitchers. However, since it was an interleague game, is will not be recognized as a record for any particular league.

Source:
Baseball Reference August 14
National Pastime
Retro Sheet
Hall of Fame
SABR Games Project
Replay The Game