On April 23, 1944 — At Braves Field, Jim Tobin of the Boston Braves pitches a one-hit 6 – 0 shutout against the Philadelphia Phillies in the Braves’ home opener. Philadelphia second baseman Ford Mullen gets the only hit in the 6th inning. In his previous start, Tobin lost a three-hitter to the New York Giants, 2 – 1, at the Polo Grounds.

Source
Baseball Reference April 23