On September 29, 1945, the Chicago Cubs' fireball pitcher Paul Erickson threw a curve ball to Tommy O'Brien of the Pittsburgh Pirates with two outs in the bottom of the ninth inning. O'Brien's knees buckled, as any hitter's knees would when he expects a fastball but gets a curve instead. O'Brien had reason to be surprised - it was Erickson's first curveball of the game, and some even claim that it was his first of the year. The ball crossed home plate for strike three. The Cubs won 4-3 and captured the National League championship.
The Cubs' journey to the National League pennant in 1945 is detailed here. The author interviewed nine surviving members of the 1945 Cubs, including pitchers Erickson, Hank Borowy, Hank Wyse and Claude Passeau, second baseman Don Johnson, shortstop Lenny Merullo, backup catcher Dewey Williams, first baseman Phil Cavaretta, and outfielder Andy Pafko, and includes their recollections of that magical Cubs season.