The Minnesota Twins’ Mudcat Grant tosses a 6 – 0 shutout against the Washington Senators, despite allowing 13 Nat hits. The record for most hits allowed in a 9-inning shutout is 14, done twice before.

On July 15, 1964 The Minnesota Twins’ Mudcat Grant tosses a 6 – 0 shutout against the Washington Senators, despite allowing 13 Nat hits. The record for most hits allowed in a 9-inning shutout is 14, done twice before.

Source
Baseball Reference July 15