On August 6, 1971 — The Yankees kayo Pat Dobson in the 4th, beating the Orioles, 12 – 3. The loss ends Dobson’s win streak of 12 games, his nine consecutive complete games, and his consecutive scoreless inning streak of 23.

Source:
Baseball Reference August 6
National Pastime
Retro Sheet
Hall of Fame
SABR Games Project
Replay The Game