On August 4, 1934 — Phillies P Reggie Grabowski surrenders 11 hits in the ninth inning of the second game against the Giants for a modern National League record. Eleven runs score in the inning, as New York wins, 21 – 4.

Source:
Baseball Reference August 4
National Pastime
Retro Sheet
Hall of Fame
SABR Games Project
Replay The Game