On July 17, 1974, Bob Gibson recorded his 3,000th career strikeout when he fanned Cesar Geronimo during the second inning of a 12 inning 6-4 loss against the Cincinnati Reds at Busch Stadium in St. Louis. The Cardinals led 4-3 after three thanks to home runs by Joe Torre and Reggie Smith, but the lead disappeared after the Reds scored a run in the fourth, then another in the sixth. Gibby was lifted for a pinch hitter in the eighth. His final pitching line for the day was seven innings pitched, four strikeouts, and the four earned runs. The four K's put him at 3,003 for his career. The teams stayed deadlocked until that fateful twelfth, when George Foster hit a two run double that decided the contest. While the final score was not what the Cardinals and their fans had hoped for, the game was historic, as Gibson had moved behind only Walter Johnson on the all time strikeouts list. Gibson finished his career with 3,117 strikeouts.
Check out the box score here: http://www.baseball-reference.com/boxes/SLN/SLN197407170.shtml