On July 8, 1962 — Cincinnati uses nine pitchers to win the 13-inning second game against the Houston Colt .45’s, 12 – 11. This sets a National League record and ties the major league mark. Houston scores once in the 13th and Cincy scores twice to win. The Reds also win the first game, 12 – 8, battling back from an 8 – 3 deficit.
Source:
Baseball Reference July 8