In Chicago‚ the Giants sweep a doubleheader with the Cubs to inch closer to 2nd place. New York wins the opener‚ 5 – 2‚ then Christy Mathewson sets down the Cubs‚ 3 – 0‚ for his 18th win.

On August 12, 1909 — In Chicago‚ the Giants sweep a doubleheader with the Cubs to inch closer to 2nd place. New York wins the opener‚ 5 – 2‚ then Christy Mathewson sets down the Cubs‚ 3 – 0‚ for his 18th win.

Source:
Baseball Reference August 12
National Pastime
Retro Sheet
Hall of Fame
SABR Games Project
Replay The Game