On August 21, 1947, the Cardinals pounded the Phillies 13-3 behind a two home run performance by Stan The Man Musial in the second game of a doubleheader at Shibe Park in Philadelphia. The Birds were looking to bounce back after dropping the first game 9-3 and it looked like the Phillies might just have their number as they plated three runs in the first two innings which led to an early hook for Cardinals starter Jim Hearn. With two outs in the second Al Brazle took over pitching duties for the Birds and he got the job done. Brazle allowed just 5 hits and went the rest of the way for the Cards. The Man's first blast was a third inning solo shot that put the Cardinals on the board. In the fourth, Ron Northey put the Birds in front with a three run bomb. When Musial came to the plate in the sixth the sacks were jammed and with one swing of the bat Musial cleared the basepaths with a grand slam. The Cards tacked on 4 more in the seventh as they sailed to the 13-3 victory. Musial hit 19 of his 475 home runs at Shibe Park.
Here's the box score: http://www.baseball-reference.com/boxes/PHI/PHI194708212.shtml