“Mr. Cub” Ernie Banks hits his 4th grand slam of the season, tying the major league record, as Bob Rush bests the Pirates, 12 – 4.

This Day In Baseball

On August 2, 1955 — “Mr. Cub” Ernie Banks hits his 4th grand slam of the season, tying the major league record, as Bob Rush bests the Pirates, 12 – 4.

Source:
Baseball Reference August 2
National Pastime
Retro Sheet
Hall of Fame
SABR Games Project
Replay The Game