On July 7, 1948, the Cleveland Indians stunned MLB by signing 42 year old veteran of the Negro Leagues pitcher Satchel Paige. It was his 42nd birthday. He became the first black to pitch in a World series game, and he and Larry Doby were the first blacks to win a World Series Championship. Paige finished at 6-1 with a 2.48 ERA. An excerpt from the article:
"Paige, conversely, was a nightmare for opposing batters, as he had a 2.48 ERA in seven starts and 21 games total. He finished the second half of the season 6-1 with three complete games. In Game 5 of the World Series, Paige pitched two-thirds of an inning, getting the final two outs in the seventh inning. The first out was a fly ball that Doby fielded in center field.
Even with me going on 42, the way I was throwing, I felt I was too young to take any cut in pay,” Paige wrote in his autobiography, Maybe I’ll Pitch Forever. “After 22 years of throwing, I was going to get a crack at the major leagues.”
The Indians clinched the title with a 4-3 victory in Game 6 on Oct. 11, 1948."